This document was written by Gus Cairns of Positive Nation and thus contains some United Kingdom-specific information. Please note that this document was written in 2000-2001 so some of the information needs to be updated. FIAR will be providing more information to augment this document.

Taking vitamin, mineral or other supplements is probably the most popular 'complementary therapy'. The UK population currently spends over £400 million a year on vitamin and nutritional supplements - though this is dwarfed by the health-conscious Americans, who in 1999 spent $15.7 billion.

A collective term used for these compounds is 'micronutrients'. This contrasts them with the macronutrients, the proteins, carbohydrates and fats that make up the bulk of food. The term signifies that only small and in some cases minute amounts of these substances are necessary for health, though those amounts are essential.

It may also be a misleading term, however, in that it suggests that taking vitamin supplements can substitute for a good diet, or make up for a poor one. It may also reinforce the probably illusory idea that somewhere out there is a simple vitamin or herbal remedy, a few pills of which a day would do away with the need for good self-care or conventional medicine.

With certain exceptions, the best way to get vitamins and minerals is generally to eat a balanced healthy diet, rather than spending money on expensive purified chemicals. Many vitamins and minerals work best, or are only absorbed well, in combination with other substances in food.

Although the primary vitamins have been known about for nearly a century, many aspects of their functioning remain mysterious. For instance, while vitamin B2 deficiency clearly causes cracked skin and lips, the biochemistry of this effect remains unclear. There is a lot of mythology about the properties of vitamins. It is almost universally believed, for example, that vitamin C cures colds. But at least 16 double-blinded studies have found almost no benefit. A classic study by the University of Toronto ⁽²⁾ divided 3,500 people into eight groups. Six of the groups received 250, 1,000 or 2,000 mg of vitamin C daily or twice daily: the final two groups received a placebo. It was found that the vitamin C supplementation showed no ability to prevent colds, and that the most that could be said was that 250mg of vitamin C slightly decreased symptom severity for some. The higher doses produced no additional benefit.

Since the beginning of the AIDS epidemic, taking vitamins, minerals and other nutritional supplements has been one of the ways people with HIV have tried to preserve their health. In the days before antiretroviral therapy, trying different substances was an inevitable part of the search to find something that would reverse or at least slow disease progression. The following paragraph ⁽³⁾ from a 1992 article in The GHMC Newsletter of Experimental Therapies exemplifies the thinking of many people in the early 90s:

There was a hope that, in the absence of effective drugs, there had to be a cure out there somewhere in the array of 'natural' remedies, if only one could find the exact regime.

However, as the reference quoted makes clear, these experimental supplementation strategies often involved 'megadosing' - taking huge doses of vitamins, sometimes intravenously. There is little evidence that this strategy worked any better than regular supplementation, as another quote ⁽⁴⁾, from the Bulletin of Experimental Treatments for AIDS (BETA) says:

These megadoses were often part of complex and exacting regimens that were more demanding to take than HAART, and while many PWHIVs used simple multivitamin supplementation, others tried remedies ranging from ones whose usefulness has stood up to a certain amount of scientific scrutiny - antioxidants like n-acetyl cysteine (NAC), for instance - to ones that were useless, exorbitantly expensive, or even potentially toxic, such as the mineral germanium, or swallowing dilute hydrogen peroxide.

This strand of alternative self-medication has always existed alongside the quest of orthodox medicine to treat HIV. As our knowledge has progressed, the two strands have informed and reinforced each other, and our knowledge of the usefulness, or otherwise, of many supplements continues to advance.

There is also a 'quality problem' in that many supplements, particularly the more expensive ones, sometimes contain little or none of the active ingredient. For instance, in a recent American survey ⁽⁵⁾, tests of supplements of the hormone DHEA found that only seven had DHEA content to within 90-110% of the label claim. In three no or virtually no DHEA was found. A similar test of ginseng products found that some contained no ginseng at all. And a test of supplements containing the supplement chondroitin sulphate, often used for arthritis and joint problems, only five of 32 products contained 90-100% of the level of active ingredient claimed, 17 containing less than half the amount on the label. On a few occasions supplements have been found to contain far more of the active ingredient than stated.

More frequently, supplements are presented in a formulation that is useless because it is not bioavailable - cannot be easily digested. One cannot, for instance, just eat chalk to get more calcium; like many minerals, it has to be in an organically-bound form.

Other supplements are antagonists. An excess of one will lead to a deficiency of the other. For instance, taking too much folic acid interferes with zinc absorption. So dosage of one substance should be carefully limited, or both substances need to be taken in a balanced formulation. Examples are vitamins B1 and B2; folic acid and B12; and calcium and magnesium.

You should always let your doctor know what supplements you are taking, and you should not take more than is good for you. While some supplements are not toxic, others, such as vitamins A, B6 and D, and minerals like zinc, are toxic in amounts not hugely greater than the recommended daily amount. Others like vitamin C, while not toxic as such, may cause side effects like diarrhoea or kidney stones, as well as interfering with iron absorption, as mentioned above.

Others should not be taken alone as they interfere with the absorption of other vitamins. Vitamin B1 (thiamine), for instance, if taken alone, can cause deficiency in the levels of vitamin B2 (riboflavin); too much phosphorus in the diet may interfere with calcium absorption; and long-term use of too much zinc may interfere with the body's ability to absorb copper, another important trace element. For this reason it is usually better to take a good multivitamin/mineral supplement rather than taking individual supplements, apart from those not normal found in multivitamins such as NAC and LAC.

If the RDA is significantly larger than the 'average from diet' column in the table below, it means this particular substance may need to be taken as a supplement by the average person. US RDAs differ between men and women.

People with HIV are by definition not 'averagely healthy'. This does not mean their RDAs will be different, but it does mean that they may have additional needs that the RDAs do not meet.

The table below shows the EU and US Recommended Daily Allowance of vitamins and minerals and the recommended maximum safe doses.

*Average from diet. A European figure from the Health Supplements Information Service, based on the average European diet. This is the average for men and women: men may get up to 25% more than this form their diet, and women up to 25% less.

*Upper safe limit. A European figure from the EMEA. The upper safe level that should be taken from supplements alone assuming an average European diet is consumed.

*Tolerable upper intake level. A US figure from the Food and Drug Agency defined as "The highest total level of a nutrient consumed from both diet and supplements which is unlikely to pose adverse health effects to almost all individuals in the general population."

*Toxicity threshold. The level above which toxicities have been observed.

1. For long-term use or in pregnancy. Up to 7500mcg (25,000 IU) is safe for short-term use (a few weeks).
2. In the absence of taking a vitamin A supplement as well. 12 micrograms of β-carotene convert to approximately one microgram of vitamin A in the body.
3. Taking B1 (thiamine) or B2 (riboflavin) alone can interfere with the absorption of the other vitamin.
4. In the form of nicotinic acid. Nicotinamide seems to be safer.
5. Pantothenic acid is also provided by intestinal bacteria.
6. Taking too much pantothenic acid can interfere with absorption of vitamin B1.
7. 2.2 mg for pregnant women.
8. But interferes with absorption of vitamins B1 and B6.
9. High doses of folic acid cause problems in zinc absorption.
10. 2.2 mcg for pregnant women.
11. May be considerably lower in vegans: B12 is the only vitamin with no plant sources.
12. Folic acid and vitamin B12 potentiate each other and should preferably be taken together.
13. Experimental high-dose intravenous B12 has resulted in occasional allergic reactions.
14. Considerably more can often be tolerated if doses are built up to gradually. They should also be tapered off gradually, as the body builds up tolerance to vitamin C, and sudden reductions can cause scurvy.
15. Above this level, often causes diarrhoea, intestinal discomfort. May cause kidney stones in those susceptible.
16. The balance is usually made up by the action of sunlight on skin.
17. International Units are a measure of biological activity rather than weight. Unlike other vitamins, Vitamin E is a mixture of different compounds (alpha to delta tocopherols) with differing amounts of biological activity. So Vitamin E IUs are difficult to translate directly into milligrams as it depends on the mix of tocopherols provided.
18. Taking more than 600 IU of vitamin E a day has been observed to interfere with beta-carotene absorption and utilisation.
19. Varying amounts of vitamin K are contributed by intestinal bacteria.
20. Toxicity rare: usually restricted to people taking anti-coagulant drugs.
21. Best combined with magnesium to ensure bioavailability.
22. 1500 mg after age 65.
23. 27 mg in pregnant women - this amount is not easily available in the diet and should be supplemented. 8 mg in post-menopausal women. Men and post-menopausal women are unlikely to need iron supplementation, and it may be toxic.
24. NB: Taking more than 15mg elemental zinc a day long-term is associated with faster immune decline in PWHIVs. High doses interfere with copper absorption.

Nonetheless, we actually know more than we did in 1992 as to exactly why supplementation may improve health and survival rates in people with HIV. In the HAART era, vitamin and mineral supplementation is still useful for a variety of reasons in several key, and overlapping, areas:

The vitamins were first discovered because severe deficits cause deficiency diseases like beri-beri (Vitamin B1 deficiency) and scurvy (vitamin C deficiency). This is a long way from their reputation as cure-alls, which sustains a multi-million pound supplements industry today. Nonetheless, many studies have been done which show tantalising statistical relationships between micronutrient levels and certain illnesses. The reason why a diet high in fruit and vegetables, for instance, appears to protect against certain cancers appears to be related to the antioxidants (see below) that they contain. In HIV disease, taking anti-oxidants may help the body fight cancers too.

Again, while the most rigorous double-blind studies have failed to prove that vitamin C prevents colds and flu, it does appear to protect against heart disease. Some of the evidence points to vitamin E having an even more protective effect: likewise the mineral selenium and the supplement l-acetyl carnitine. Short courses of the mineral zinc really do seem to have some protective effect against colds⁽²⁾. Another popular class of supplements is the 'probiotics'. These contain bacteria such as the Lactobacillus species, which turn milk sour and naturally inhabit the large intestine, where they help the process of digestion. They help keep fungal infections like Candida in check, and people with lowered immunity, and those who have taken courses of antibiotics which kill off the normal intestinal 'flora', may benefit from taking Lactobacillus is the form of live yoghurt or in capsules.

Many people with HIV decide to take extra vitamins and minerals to try directly to protect or strengthen their immune systems. Evidence that they help is controversial, but studies have shown that people with HIV may have less of some vitamins in their bloodstream than uninfected people, including vitamins A, E, B6, B12 and folic acid, the minerals selenium and zinc, and the sulphur-containing amino acid cysteine. The benefits of vitamin therapy in directly combating HIV disease remain controversial. A large study conducted in South Africa ⁽⁷⁾ found that a daily vitamin B complex and multivitamin delayed the onset of AIDS and death. While the result suggests that nutritional status may affect the course of HIV disease, it is not known whether vitamin supplements delay HIV disease progression among people with superior nutritional status compared with participants in this study.

We do know, however, that various studies have shown either a statistical relationship between micronutrient levels in the bloodstream and morbidity/mortality rates, or have shown that HIV infection seems to lead to a loss of certain micronutrients from the body. It may therefore be a good idea to take a multivitamin and mineral supplement each day that contains more than the recommended daily intake for the general population. Your clinic or GP may be able to prescribe this multivitamin supplement.

The process of metabolism - of life itself - is essentially a controlled burning of carbon-based organic substances in the presence of oxygen. Oxygen, however, is also the second most reactive of the elements and can cause the devastation of a forest fire as well as the warmth of a hearth. The 'sparks' from the fire of metabolism are the so-called 'free radicals' - chemically unstable and therefore extremely reactive oxygen-containing ions (charged molecules) which cause damage to tissues by oxidising them - much as iron is oxidised to rust.

There is an arsenal of chemicals, the antioxidants, contained in food and produced in the body whose job is to mop up free radicals before they cause damage. These include the enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase; glutathione itself; vitamins C and E; various carotenoids, including vitamin A; and related plant chemicals like the bioflavonoids and polyphenols. During many diseases, especially chronic ones like HIV infection, an abundance of free radicals appear to be produced as a side-effect of immune system activation. In addition, or because of this, it appears that the body is progressively depleted of certain antioxidant compounds during HIV infection. A state of oxidative stress develops in which various types of tissue damage occurs.

Lipids (fats) are particularly vulnerable to oxidation. The membranes on and within cells, particularly immune cells, contain a high percentage of polyunsaturated fatty acids (lipids), as do arterial walls, the myelin sheath that insulates nerves, and many other vital body tissues. Free radicals can degrade these tissues, leaving important cellular components unprotected, causing hardening of the arteries and cardiovascular disease, and damage to the nervous system. Cells' genetic material also can come under attack, resulting in mutations. Supplementation with the best-known antioxidants such as Vitamins A, C and E, glutathione and alpha lipoic acid may therefore be particularly valuable for people with HIV.

The side effects caused by antiretroviral and other drugs may be prevented or reduced by judicious supplementation.

The side effects where there is evidence of vitamins and supplements having a helpful role include various ones associated with the nucleoside drugs. These include hyperlactatemia, an excess of lactic acid, a waste product of metabolism, in the blood, which occasionally progresses to the life-threatening complication lactic acidosis. This can also manifest as myopathy or damage to the muscles, including damage to the heart muscle. Similar toxicities can cause nerve damage, which may manifest as peripheral neuropathy; and an accumulation of fat in the liver, known as hepatic steatosis. Whether these have a common underlying cause is yet to be proved, but they may all be connected to damage to the mitochondria, the energy-producing components of cells.

The B vitamins, in particular vitamins B1, B2 and niacin, have been used as 'emergency therapy' in cases of lactic acidosis, and may protect against such damage occurring in the first place. The vitamin-like compound carnitine, which transports substances across the membranes of the mitochondria, is also part of this rescue therapy. It has also been shown to repair damaged nerves in cases of peripheral neuropathy, and has also been used to protect the kidneys from damage by drugs like adefovir. Some doctors are willing to prescribe this supplement. The compound coenzyme Q-10 or ubiquinone performs a similar energy-transporting function in muscles, particularly in heart muscle, and may protect against myopathy. And the anti-oxidants help to protect liver cells against damage.

Protease inhibitor therapy may increase the risk of cardiovascular disease: taking vitamin C may protect against this, as may folic acid, which acts as an antagonist to a substance called homocysteine which is associated with a greater tendency to heart disease in certain individuals. Vitamin E may also protect against heart disease.

A group of side effects that have more recently come to light are bone problems such as osteoporosis and osteonecrosis. While the cause of these remains unclear, balanced supplementation with calcium, magnesium and vitamin D may help to preserve bone strength.

Both protease inhibitors and HIV infection can cause diarrhoea: supplements that many people find help relieve this again include calcium, the amino acid l-glutamine, and probiotic supplements of intestinal bacteria (Lactobacillus, etc), while potassium supplementation may be necessary in chronic cases.

The anti-PCP drug Septrin (co-trimoxazole, Bactrim) works by interfering with micro-organisms' ability to use folic acid: although folate supplementation has not been shown to reduce Septrin allergy, the drug may interfere with the body's ability to use folate in a longer-term way. Vitamin B12 and folic acid work in conjunction with each other and should be taken together.

A lot of the general, as opposed to specific, evidence of the benefit of vitamin supplementation in people with HIV comes from two early studies; one by Abrams in San Francisco, reported in August 1993⁽⁶⁾, and one by Tang of the Johns Hopkins University in Baltimore, reported in December 1993⁽⁸⁾.

The Tang study took 280 patients out of the Multicentre Aids Cohort Study (MACS) and analysed their micronutrient intake both from diet and supplements. Certain micronutrients were found to have considerable influence on both progression to AIDS and death. High intakes of vitamins B1, niacin and C were associated with slower progression to Aids. The 25 per cent of the patients with the highest intake of vitamin C, for instance (they averaged 715mg/day) had 55 per cent of the average chance of progressing to Aids over the course of the study.

Only two micronutrients broke the pattern. The lowest risk of progression or death was associated with the patients taking moderately increased, as opposed to high, doses of beta-carotene; and any zinc intake more than 5mg over the RDA of 15mg was associated with greater risk of Aids or death.

In terms of the risk of death, as well as vitamins B1, niacin and C, vitamins B2 and B6 considerably reduced the risk. Patients taking about twice the RDA of vitamin B6, for instance, had less than half the risk of dying.

The Tang study could not prove that it was the micronutrients that were slowing progression to AIDS and death, or if so, how. The diet questionnaires they gave people at the start of the study were not repeated, so the study could not factor in changes in diet (for example if people ate less well as they became more ill). Nor could it control for those who ate better and took supplements also looking after themselves better in other ways. And this pre-HAART era study cannot factor in the additional influence on morbidity and mortality of using vitamins to combat the side effects of anti-HIV drugs.

Nonetheless, the considerable differences in morbidity and life expectancy associated with some vitamins are very suggestive. There is probably no point in waiting for better evidence: detailed cohort studies of how individual micronutrients influence the course of HIV infection will probably never be done.

But the cheapness and availability of most micronutrients mean that PWHIVs can, and maybe should, be encouraged to 'self-medicate', as long as doses are kept within the limits on the table above. (NB a multivitamin supplement should be one, ideally, with higher levels of B vitamins and lower levels of vitamin A and zinc. Men and post-menopausal women should avoid multivitamins containing iron).

Vitamin A was the first vitamin to be discovered. It is essential for normal vision, growth and development, and a healthy immune system. The animal form of vitamin A is found in milk, liver, fish, cheese, butter, and eggs.

In this form, vitamin A in excess is toxic. (See table above and details below). Vitamin A in excess can cause nausea, vomiting, headache, bone and joint pain, and, in extreme cases, liver damage. When taken in high doses over a long period of time, vitamin A can cause serious liver and skin toxicities. It also has a tendency to cause birth defects.

There is also a plant form of vitamin A called beta-carotene. (Other forms of carotene also convert to vitamin A in the body, but not as efficiently). Carotene is water soluble and not toxic. With beta-carotene you get two for the price of one: it converts to do all the things that vitamin A can do, generally without the toxicity, and it works as an antioxidant, protecting your cells. Foods rich in beta-carotene include orange or dark green vegetables such as carrots, sweet potatoes, pumpkins, cantaloupe, spinach, kale, and broccoli.

A study in HIV-negative people suggested that beta-carotene is best absorbed when split into three doses during the day and taken with (ideally fatty) food. Beta-carotene is usually taken with `rest periods', such as taking it for 20 days out of every 30. The rest period is assumed to be necessary to avoid the gradual lessening of the immunomodulatory effects of the vitamin.

The only usual side effect of high doses of beta-carotene is the acquisition of orange skin tone. When this happens it means that fatty tissues are saturated with the vitamin.

It is important to emphasise that the Johns Hopkins study quoted above ⁽⁸⁾ found a 'U-shaped' dose-response in terms of progression to AIDS with beta carotene - in other words both those who took a lot and those who took very little progressed more quickly than those who took moderate amounts. Vitamin A itself was not associated with any benefit.

The study divided the group into 'quartiles' - the 25 per cent of patients who took high, high middle, low middle and low doses of beta-carotene. The patients who either took more than an average of 20,268 IUs a day (c.6.1mg) or less than 9,062 IUs (c.2.7 mg) did 55 per cent as well as the patients who took amounts in between these figures. This one study, therefore, comes out with an 'ideal dose' in both food and supplements of around 4mg/day. Considering that the amount obtained from the average European diet is 3.2mg/day, this would seem to indicate that more than very modest beta-carotene supplementation might not benefit health.

One non-HIV related study that also suggests this was a large study of smokers in Finland which found that far from protecting them against lung cancer, subjects that took 20mg of beta-carotene a day actually had an 18 per cent higher risk of developing it.

NB: In individuals with liver dysfunction, diabetes or hypothyroidism - all of them side effects of antiretroviral drugs - it is not possible for the liver to convert beta-carotene into vitamin A. In these individuals, who may have problems absorbing fat, it is possible to take vitamin A in a water soluble form. Heavy use of alcohol and other drugs may interfere with vitamin A absorption. Furthermore, taking vitamin A supplement in the presence of alcohol and smoking increases a person's chances of liver damage, liver cancer and pulmonary cancer ⁽⁹⁾.

Vitamin A's best-understood role is in enabling the chemical signals that light effects in the retina to be transformed into electrical ones that are transmitted to the brain. The best-known deficiency symptom is night blindness - the source of the folk wisdom that 'carrots help you see in the dark'. Vitamin A deficiency is the biggest single cause of preventable blindness the world over.

A study of pregnant women in Nepal ⁽¹⁰⁾ showed that taking a weekly dose of 42mg of beta-carotene (equivalent to 500mcg of vitamin A per day) reduced their mortality during pregnancy and childbirth by 49 per cent. Some international health experts have proposed a programme of universal supplementation in pregnant women.

Vitamin A also appears to be involved in the growth and maturation of certain kinds of cell, including those responsible for building bones, teeth, and hair, the cells of the endocrine glands, skin cells - and immune system cells including CD4 and CD cells.

Several studies have shown that vitamin A plays an important role in the immune system. Animal studies have shown that a shortage of vitamin A can cause immune problems and disease.

In areas where vitamin A deficiency is more common, such as parts of India, providing supplements of vitamin A has been shown to decrease childhood mortality from infectious disease. One study showed a startling 54 per cent decline in childhood mortality among infants randomised to receive weekly Vitamin A supplements (8333 IU - 2500 mcg) or Vitamin E (20mg) for over one year.

It is unclear, however, whether taking supplements of vitamin A can reverse deficiency or improve the clinical outcome of people with HIV.

Studies have suggested that some people with HIV have vitamin A deficiency ⁽¹¹⁾ and that this may be associated with lower CD4 counts and an increased risk of mortality. Vitamin A deficiency may be a secondary consequence of malnutrition in people with HIV or could be a consequence of HIV infection itself, since infection and fever are known to cause depletion of the vitamin. In the test-tube, vitamin A increases HIV replication in some cell types and decreases replication in others.

Beta-carotene levels have been found to be low in HIV-infected individuals also ⁽¹²⁾, particularly those with more advanced disease. Beta-carotene was shown to improve symptoms and stabilise CD4 counts in a small two-year study ⁽¹³⁾ conducted amongst HIV-positive people in Italy (60 mg/day for 20 days out of 30). In another double-blind study ⁽¹⁴⁾, supplementing with high doses of beta-carotene (300,000 IUs/90mg, equivalent to 25,000 IUs or 7500 mcg of vitamin A) significantly increased the number of CD4 cells in certain individuals. However a later study ⁽¹⁵⁾ by the same author found no overall effect on CD4 cell counts. No immunological or virological changes were reported after 4 weeks, and people with low baseline vitamin A blood levels were no more likely to have significant changes than people with normal baseline vitamin A levels.

One study has suggested that HIV-positive pregnant women in Africa who have vitamin A deficiency may be more likely to transmit HIV to their children ⁽¹⁶⁾. However, in a study of American women ⁽¹⁷⁾, no association between vitamin A levels and risk of transmission was seen, suggesting that this may not be a significant factor in industrialised countries. Moreover, taking too much vitamin A during pregnancy increases the risk that the child will have birth defects. A large placebo-controlled, comparative trial in Tanzania ⁽¹⁸⁾ found that vitamin A had no effective on foetal deaths, preterm delivery or small birth size; however, multivitamin supplements did improve pregnancy outcomes and the CD4 and CD8 levels of the women.

The role of vitamin A as an antioxidant is not entirely understood, but vitamin A deficiency has been linked to oxidative stress in HIV-positive patients. A fashion for taking megadoses of beta-carotene as an antioxidant in the early 1990s has somewhat declined, as other antioxidants gain a higher profile.

In 1995, a French research team ⁽¹⁹⁾ studied 95 HIV-positive volunteers for a decrease in polyunsaturated fatty acids and an increase in lipid peroxidation, which the authors considered a sign of oxidative stress. Such lipid alterations were noted in study participants with CD4 counts below 400, but no correlation was found between these markers and levels of the antioxidant nutritional components selenium, vitamins A, C and E.

The B vitamins are a mixed bag of eight water-soluble vitamins. Some are known by their vitamin number, and others by their name, though all in fact have both vitamin numbers and at least one chemical name - a confusing situation (see table):

Although the B vitamins all have different biochemical functions, the jobs they do in the body overlap, and deficiency of one or more B vitamins, or the presence of conditions they normally prevent, present similar symptoms. For this reason it makes sense to deal with them all together. In addition, taking one B vitamin as a supplement in isolation tends to lower levels of the others in the body.

These vitamins are involved in the release of energy from food, in the synthesis of red blood cells, in the health of nerve cells, and in the synthesis of steroid hormones such as adrenalin.

Vitamin B deficiency presents a common picture of fatigue, weakness, nausea, digestive problems, aching muscles, damage to the liver and pancreas cells, and sometimes confusion or dementia.

Until recently the B vitamins were not as popular or fashionable as supplements among people with HIV as other supplements such as beta carotene or n-acetyl cysteine (NAC). The one exception was vitamin B12, seen by some nutritionists as chronically deficient in people with HIV and a possible cause of dementia. This has all changed with the toxicities seen in the longer-term use of antiretroviral drugs, and particularly the nucleosides.

The clinical picture presented by B deficiency looks very similar to the symptoms of mitochondrial toxicity, and to its often fatal complication, lactic acidosis. Although the exact clinical picture has yet to be understood, it is known that the nucleoside drugs, to a greater or lesser degree, damage the genetic material of the mitochondria, the 'powerhouses' in the cells that turn food into energy. Specific nucleosides are associated with specific kinds of damage to other cells, too: AZT to red blood and muscle cells, d4T and ddC to nerve cells, ddI to the pancreas, and so on.

It was a reasonable hypothesis, then, that supplementing with B vitamins might help the remaining mitochondria work more efficiently and preserve other types of cell from damage.

In emergency cases this supposition has been quite dramatically confirmed.

A team of Dutch doctors ⁽²⁰⁾ treated patients with lactic acidosis (defined as a serum lactate level of over 5 mmol/L and a bicarbonate level of under 20 mmol/L) with the following twice-daily intravenous 'rescue regimen':

(L-carnitine does a similar job to the B vitamins, helping to transport energy-creating chemicals across cell membranes.) Recovery was defined as a fall in the serum lactate level to below 3 mmol/L. The results were very encouraging: all of the first six patients recovered in time scales varying from four days to three weeks. Mortality from lactic acidosis normally runs at over 50 per cent.

The use of vitamins as 'emergency therapy' must be distinguished from normal supplementation and there is only anecdotal evidence that B supplementation prevents nucleoside side effects. But other studies recently have shown a greater health benefit from B vitamin supplementation in PWHIVs not taking antiretroviral treatment than any other vitamins. One South African study ⁽²¹⁾ presented at the 13th World Aids Conference studied 2100 patients at Johannesburg General Hospital HIV Clinic.

In this study, the median time to AIDS in patients taking a multivitamin was 71 weeks compared to 33 weeks for those not taking one. Even more striking was the AIDS-free time associated with a B complex vitamin. The median time to progression for those taking vitamin B complex was 152 weeks versus 32 weeks among those who did not. The data were less impressive but still important for those who had already progressed to AIDS. Median survival among AIDS patients taking vitamin B complex was 62 weeks compared to 42.5 weeks in those who did not. Since these data were obtained from a retrospective chart review and not a controlled clinical trial, it is possible that other, intervening variables influenced the results. For example, the vitamin takers may have been individuals who generally took better care of their health than the non-vitamin takers.

Alcohol consumption interferes with the absorption and storage of this vitamin, which is essential in the formation and maintenance of muscle and efficient use of carbohydrates as energy in the body. Requirements for thiamine probably increase during feverish illness as the demand for carbohydrates increases. Extreme deficiency, seen in tropical countries where the thiamine-containing husk and germ of the staple diet, rice, were formerly removed, causes the deficiency disease beri-beri, characterised by nausea, depression and/or anxiety, muscle cramps and heart irregularities. Beri-beri is rarer now that brown rice has come to be a more acceptable diet.

In industrial countries, not only alcoholics, but also deprived people with malnutrition, elderly patients and people with symptomatic AIDS are at risk of thiamine deficiency through malnutrition or malabsorption.

In the Tang study ⁽⁸⁾, the 25 per cent of patients with the highest intake of thiamine (from food and supplements) - about three times the RDA (average 4.9mg) - had a 40 per cent reduction in the risk of progression to Aids.

Some cardiovascular symptoms in PWAs with malabsorption or alcohol problems may be caused by thiamine deficiency. Cardiovascular or so-called 'wet' beri-beri is characterised by peripheral vasodilatation with increased cardiac output, lesions in the heart muscles, sodium and water retention and biventricular heart muscle failure. Treatment with thiamine ⁽²²⁾ leads to rapid clinical improvement.

In the early 1990s, scientists suggested that thiamine supplementation could help with a specific form of encephalopathy ⁽²⁴⁾. Four post-mortems of people who had died with AIDS showed evidence of Wernicke's encephalopathy, a condition resulting from thiamine deficiency. Butterworth et al. studied 39 PWAs at different stages of AIDS for signs of Wernicke's encephalopathy. No patients were found have overt symptoms, but thiamine deficiencies were present in nine of them. The researchers concluded that many PWAs could be at risk for Wernicke's encephalopathy, and that thiamine could prevent the condition. It is not known if this may still be a factor in patients with malabsorption.

Vitamin B2 is an essential building block for glutathione, a key anti-oxidant. Deficiency symptoms include cracking at the corner of the mouth and on the lips. Diets low in dairy products are especially likely to be deficient. Riboflavin is a strong yellowish-green pigment, and a guide to how much the body may require at any one time (along with other B vitamins in proportional amounts) is that unused B2 colours the urine.

In the Tang study ⁽⁸⁾, the 25 per cent of patients with the highest intake of riboflavin (average 5.9mg, about 3.5 times the RDA) in food and supplements had a 40 per cent decrease in the likelihood of death or progression to AIDS.

Niacin (nicotinic acid or nicotinamide) is one of the B vitamins that help convert food to energy. It also seems to support the integrity of the gastrointestinal tract, and deficiency can result in severe diarrhoea, which then exacerbates deficiency. Niacin is also responsible for the synthesis of steroid hormones from cholesterol and the fatty acids. Severe deficiency causes the condition pellagra, which was common in Europe and the USA before World War II, but which has now been virtually eliminated with the fortification of bread and cereals with niacin. The symptoms of pellagra are severe diarrhoea, skin and mouth sores, and mental confusion.

In the Tang study quoted above ⁽⁸⁾, the 25 per cent of patients with the highest intake of niacin from food and supplements (averaging 61mg, or about four times the RDA), had only half the likelihood of progressing to Aids (risk ratio: 0.52). Certain doctors still recommend niacin as an 'Aids preventative factor' ⁽²⁵⁾, and urge supplementation as an aid to reducing the death rate due to AIDS in the developing world.

More recently, niacin's role in the metabolism of cholesterol has suggested it might be useful in the control of lipodystrophy and high blood lipids in patients taking protease inhibitors or other antiretrovirals.

To test this idea, doctors in San Francisco ⁽²⁶⁾ recruited six HIV-positive subjects taking HAART who had experienced an increase in abdominal fat while on therapy. Subjects took niacin orally in gradually increasing doses until they were able to tolerate 1,000 mg three times daily - 50-60 times the RDA. Those subjects who were able to take this amount of niacin for more than three months had decreased abdominal fat (measured by CAT scans) as well as significantly increased levels of good cholesterol. Triglyceride levels fell during the study, but this decrease was not statistically significant. 1,000mg is nearing the toxicity level, though toxicity seems to be less if niacin is taken in the form of nicotinamide rather than nicotinic acid.

Vitamin B-6 is crucial to many biological processes, including, most importantly, amino acid metabolism and biosynthesis. Vitamin B6 is essential for the formation of new cells and for maintaining immunity. Studies in animals show a range of immune defects when the diet is deficient ⁽²⁷⁾. It is found in most foods, but meat provides the most usable form of the substance. White bread and other grains are often fortified with the vitamin. Vitamin B-6 deficiency is considered rare in human populations, although marginal deficiency may occur more frequently.

Like B12, B6 is also involved in the health of the nervous system. It is involved in the synthesis of the neurotransmitter serotonin, the 'anti-stress' neurotransmitter that is overproduced in people who take ecstasy (MDMA). Deficiency of vitamin B-6 produces profound skin and neurological changes, including depression and peripheral neuropathy. The tuberculosis antibiotic isoniazid reduces vitamin B-6 levels, so they are usually co-administered.

Little is known about this vitamin's role in immunity or its mechanism of action, although it appears to play a significant role. Animal studies suggest that B-6 deficiency has a range of effects on cell mediated immunity. Vitamin B-6 deficiency can also lead to impaired antibody production and fewer antibody-producing cells in animals, according to various studies.

Few human studies address the issue of vitamin B-6 and immunity, and those that have examined the question demonstrate no consistent direction of effect. Two studies of vitamin B6 deficiency in humans show that it may slightly impair antibody production or leave it unchanged.

There has been little research directed at Vitamin B-6 and AIDS. The Tang study quoted above ⁽⁸⁾ found that the 25 per cent of patients consuming an average of 5.7mg of B6 a day from food and supplements - about three times the RDA - had less than half the chance of dying from Aids (risk ratio 0.47) than the remainder of patients, who consumed around the RDA level. One study examined Vitamin B-6 levels in a group of HIV-infected people and that 35 percent of subjects had overt deficiency and an additional 18 percent had marginal deficiency. The authors suggest that CD4 cell counts were lower in patients with reduced vitamin B-6. The authors also suggest that vitamin B-6 intake was inadequate in these subjects, based on food intake surveys. However, the diagnosis of vitamin B-6 serum levels is difficult. Food intake surveys are also not considered a reliable method for diagnosing vitamin deficiency.

AIDS-related wasting can both cause and be caused by vitamin B6 deficiency - a vicious circle. Vitamin B-6 levels may be reduced when tumour necrosis factor (an inflammatory cytokine) is increased, according to a study of rheumatoid arthritis patients. Furthermore, Vitamin B-6 is stored in muscle and deficiency may be related to decreased lean body weight.

One study ⁽²⁸⁾ treated 12 HIV positive people with 20-25 mg of vitamin B6 and observed a small increase in CD4 count amongst 8 of the 12 over a six month period. In contrast, an untreated control group showed no improvement in CD4 count.

Anecdotally, B-6 has been used successfully in controlling peripheral neuropathy, the side effect of certain nucleoside analogues like d4T, ddC and ddI. A report in Aids Treatment News ⁽³⁰⁾ says that a simple regimen of calcium, magnesium and vitamin B6 has been used to protect the nerves or treat peripheral neuropathy.

Dr Jon Kaiser, author of Healing HIV, recommends taking calcium 500mg, magnesium 250mg and vitamin B6 100mg twice a day, particularly for people taking d4T. If neuropathy is present, he recommends doubling the dose of B6. Another San Francisco doctor, Virginia Cafaro, recommends 1000mg calcium and 500mg magnesium twice a day, but only 100mg of B6 once a day, combined with acupuncture.

Cafaro's caution may be founded in the fact that high doses of B6 (above 1,000 and certainly above 2,000mg a day) actually cause nerve damage and peripheral neuropathy. Some high-dose B vitamin supplements can contain amounts approaching this level. The neurologist Oliver Sacks, in his famous book The Man who Mistook his Wife for a Hat, witnessed an 'epidemic' of sensory neuropathy in the 1970s among people who saw B6 as a panacea for depression.

Vitamin B-12 and folate are separate vitamins, but have similar biological roles and work together in vivo. Folate is critical to the synthesis of the genetic materials RNA and DNA. Folate deficiency can also cause neural tube defects (a birth defect in children born to mothers who consume inadequate amounts of the nutrient), and is now recommended as a supplement for pregnant women for this reason.

The main biological effect of Vitamin B-12 is probably on folate metabolism. Folate is found in most foods, although its deficiency is common in the developed world, affecting an estimated 8 to 10 percent of the population. Vitamin B-12 is produced mainly by bacteria that live in the human gut, although it is also found in meat. Vitamin B-12 deficiency used to be considered rare, except in some strict vegetarians who nonetheless manage to endure 20 to 30 years of inadequate intake, suggesting there are considerable body stores of the vitamin. Folate and Vitamin B-12 deficiency result in clinically similar syndromes, producing anaemia and neurologic symptoms.

Most Vitamin B-12 deficiency is thought to result from altered intestinal flora (perhaps due to antibiotic use) and malabsorption. Certain nutritionists have long thought that some people with HIV are chronically B12-deficient because of this.

Recent evidence supports the theory that B-12 deficiency is more common than was thought, and not just in people with HIV. According to a report in a recent issue of The American Journal of Clinical Nutrition ⁽³¹⁾, investigators found that 39 per cent of all individuals had low-to-normal levels of the vitamin in their blood and 17 per cent had levels low enough to cause symptoms of deficiency.

Age did not seem to matter, as those aged 26 to 49 years had the same vitamin B-12 status as those aged 65 to 83 years.

The report's authors say that early symptoms of deficiency include reduced sensation in the limbs, and memory and balance disturbances. Ultimately, B-12 deficiency can cause irreversible nerve damage. But since many of these symptoms are general, they are often not attributed to a vitamin B-12 deficiency, they report.

For most people, taking a regular multivitamin or eating breakfast cereal fortified with vitamin B-12 can easily prevent deficiency. Although the vitamin is found naturally in meat, it does not appear to be as well absorbed, the study reveals. Vitamin B-12 is tightly bound to protein in meat and requires sufficient stomach acidity to break it apart before it can be absorbed. In some people, particularly the elderly, insufficient levels of stomach acid mean that the vitamin is not taken up in sufficient quantities.

Very little published information addresses the role of folate and Vitamin B-12 in immunity. Folate deficiency causes impaired lymphocyte proliferation, the atrophy of lymph system organs such as lymph nodes, reduced T-cell numbers, and disordered lymphocyte proliferation in laboratory animals. Vitamin B-12 deficiency, but not folate, reduces the ability of white cells such as neutrophils to digest bacteria and infected cells.

I

The theory that vitamin B-12 deficiency may be an important cause of neuropathy, dementia and anaemia in people with HIV led some physicians to offer periodic B-12 injections to their patients. According to Dr Richard Beach ⁽³⁶⁾ injected B-12 supplements appear to improve mental functioning. Another study ⁽³⁷⁾ also showed that vitamin B12 supplementation for at least six months improved mental functioning in HIV-positive people who had been deficient; an untreated control group did not show improvement.

The clinical efficacy of this intervention remains largely unproven, however.

Since peripheral neuropathy can be caused by vitamin B12 deficiency as well as nucleoside drugs or HIV itself, this should always be ruled out before assuming that the neuropathy is HIV or drug-related. As yet there is no evidence that prophylactic treatment with vitamin B12 will reduce the likelihood that neuropathy will develop in those receiving d4T, ddI or ddC.

Absorption of vitamin B12 in HIV-positive people with gastro-intestinal problems is poor unless the vitamin is injected or taken in a form that will dissolve in the mouth and be absorbed across the mucous membranes, according to some nutritionists. This vitamin treatment is available on NHS prescription for dietary deficiency. It needs to be taken in conjunction with folate and a general B-vitamin supplement.

It has been suggested that B12 supplementation may reduce the risk of neutropenia and anaemia resulting from AZT use ⁽³⁸⁾. B12 is used in the production of thymidine phosphate, necessary both to break down AZT in the blood and to create red blood cells. Unless enough of this vitamin is present, AZT competes with red blood cells for available thymidine triphosphate. People who are already deficient in B12 when they begin AZT therapy may be more vulnerable to anaemia and neutropenia. However, a 1989 study ⁽³⁹⁾ showed that B12 supplementation does not reduce AZT toxicities once therapy has begun.

Folate levels, on the other hand, may be increased in HIV infection, according to several studies. One study suggested that intravenous drug users might have reduced folate levels because of poor access to fresh fruits and vegetables - key sources of folate. Gay men, the authors speculate, probably do not have reduced folate because of better access to fresh foods, although they present no evidence to support this hypothesis.

Folate utilisation can be impaired (producing a functional deficiency despite adequate intake) if B-12, methionine (an amino acid) or zinc are deficient. Some drug therapy such as the anti-PCP drugs Dapsone and Septrin (co-trimoxazole) can also cause functional folate deficiency.

Leucovorin, the active form of folate, is used medically as an antidote to drugs that decrease levels of folic acid. Leucovorin is used to reduce anaemia in people taking Dapsone. Leucovorin is also taken to decrease the bone marrow toxicity of sulfa drugs such as Septrin (co-trimoxazole) and in combination with pyrimethamine to decrease the toxicity of toxoplasmosis treatment. Leucovorin is used in combination with the anti-cancer drugs trimetrexate and methotrexate. Folate supplement is not that effective with Septrin because it is the ability of the body to use folate that Septrin affects rather than folate levels.

Supplements of folate are also prescribed to many symptomatic HIV-positive people due to deficiencies caused by malabsorption in the intestine. Folate deficiency is also common in smokers. Serious deficiency can lead to platelet disorders, a decrease in white blood cells and neuropathy.

Folic acid may defend against certain types of cancer to which people with HIV are particularly vulnerable. Both women and gay men infected with high-risk forms of the human papilloma virus (HPV) are some 35-70 times more likely to develop anal or cervical cancer than the general population. In one Polish study ⁽⁴⁰⁾, HIV negative women who did develop cervical cancer were 7.5 times more likely to have low blood levels of folic acid, an effect exacerbated if they also had low levels of vitamins A, C and E.

Folic acid may be useful in combating drug side effects. It has been shown to reduce the likelihood of cardiovascular disease, particularly among people whose genetic makeup causes them to have high blood levels of a chemical called homocysteine, and even more so if they also have diabetes. This may be particularly important in patients taking drugs that cause either diabetes (such as indinavir) and/or raised blood lipids (such as ritonavir and other protease inhibitors).

A Dutch study of the male population in the town of Hoorn ⁽⁴¹⁾ found that high blood homocysteine levels were associated with a 50 per cent greater risk of death due to cardiovascular disease in the next five years. In men who also had type 2 diabetes, the risk was increased by 115 per cent.

In a separate study ⁽⁴²⁾ dietary folic acid reduced blood homocysteine concentrations by 25 per cent, with similar effects in the range of 500-5,000 mcg mg folic acid daily. Vitamin B-12 (mean 500mcg daily) produced an additional seven per cent reduction in blood homocysteine.

Vitamin C is a micronutrient that is present in some food and is necessary for normal human function. Unlike virtually every other animal and plant species, humans cannot manufacture sufficient quantities of vitamin C for themselves. Instead, it has to be obtained from food. Vitamin C is found naturally in tomatoes, potatoes, many fruits and green vegetables, liver and kidney.

Vitamin C is critical to electron transport, collagen synthesis, and various metabolic processes. Its most important role is synthesising collagen, the building block of new tissue. When we get a wound, we need vitamin C to heal. It assists in the absorption of the mineral iron, the activation of the vitamin folic acid, the conversion of the amino acid tryptophan to the neurotransmitter serotonin, and the synthesis of the amino acid carnitine from dietary amino acids. A diet deficient in Vitamin C produces scurvy, the bane of sailors for hundreds of years. This is characterised by connective tissue disorders, impaired wound healing, bleeding gums, and other serious symptoms. Unlike other vitamins, marginal Vitamin C deficiency is somewhat better characterised. It may produce fatigue, muscle weakness, and impaired wound healing.

There are probably more 'myths' about the health properties of vitamin C than any other vitamin. For instance, it is an almost universal belief that it can 'cure colds'. Yet at least 16 double blinded studies have found no benefit ⁽²⁾.

Vitamin C has been proposed an antiviral agent for several diseases, beginning with a report from 1935 on the nutrient's ability to inactivate polio virus in vitro. Vitamin C was also able to inactivate other viruses in vitro, including herpes simplex, rabies, and tobacco mosaic virus. Massive doses of Vitamin C were used as a polio treatment, although they were ineffective.

There is contradictory statistical evidence about the ability of vitamin C to protect against cancer.

A study conducted by the Mayo Clinic found that Vitamin C was not beneficial as a cancer treatment. In fact, those who received Vitamin C had shorter survival, though not to a statistically significant level.

However, a study in the American Journal of Clinical Nutrition ⁽⁴³⁾ found that the 25 per cent of adults in the general population with the lowest blood levels of vitamin C had a 57 per cent higher mortality rate from all causes. The researchers did not find this was associated with a greater risk of cardiovascular disease, and suggested it was caused by a greater susceptibility to cancer. (Later studies found that vitamin C did protect against heart disease - see below.)

A study by the US National Cancer Institute in April 2001⁽¹⁷⁹⁾ of 600 people who were at risk of developing stomach cancer due to active infection by the bacterium Helicobacter pylori found that 1000mg of vitamin C twice a day, 30mg of beta-carotene, an antibiotic against H. pylori, or any combination of these three treatments, were four times as likely to experience shrinkage of precancerous abnormalities in the stomach lining than patients given a placebo.

Because of its association with the reduction on cancer and heart disease, the EU RDA of vitamin C was recently doubled from 60mg/day (a scurvy-preventing amount) to 120mg/day.

Different forms of vitamin C are available. Ascorbic acid is a highly acidic powder, which can cause stomach pain and discomfort when taken in large doses. Calcium ascorbate is a less acidic form of vitamin C buffered with calcium which tastes so unpleasant it makes some people sick. It can be dissolved in fruit juice or any liquid to mask the taste. Tablets are a much more expensive way of taking the vitamin in large quantities, but some manufacturers claim that one form of tableted ascorbate, ester-C, yields three times as much vitamin C in the body i.e. a 1 g tablet yields 3 g when metabolised.

If stopping vitamin C, the dose use should be reduced gradually, because the body develops tolerance, and sudden cessation may result in `rebound scurvy'.

The effect of vitamin C deficiency on the immune system is unclear, with contradictory evidence. There is reason to believe that vitamin C may play a significant role in cellular immunity.

In the test-tube, very high concentrations of vitamin C can prevent HIV from infecting new cells and prevent the activation and replication of HIV in dormant infected cells. Vitamin C also dramatically reduced the formation of syncytia, merged clumps of dysfunctional T-cells that form around an HIV-infected T-cell in the test tube. Syncytia tend to appear more frequently when CD4 counts are falling rapidly, and it has been theorised that their appearance may indicate an increased chance that AIDS-related illnesses will develop. "In vitro" vitamin C has also been shown to inactivate other viruses such as herpes simplex, rabies and tobacco mosaic virus.

As well as these anti-viral effects, vitamin C is required by phagocytes (immune cells which fight bacterial and fungal infections). High levels of vitamin C assist phagocytes in identifying and destroying candida and other fungi, suggesting that vitamin C may play a role in protection against fungal infections. The presence of vitamin C is also crucial to the effectiveness of enzymes in the liver that remove toxins from the body.

In the Tang cohort study quoted above ⁽⁸⁾, the 25 per cent of volunteers with the highest intake of vitamin C - averaging 715 mg or more of vitamin C per day, in food and supplements combined - had 0.55 of the average chance of progressing to AIDS. So they were scarcely more than half as likely as those with average vitamin C intake to progress during the study. The association with risk of death was less clear. Total vitamin C was associated with increased survival, but no relationship was found between vitamin C from supplements alone and survival.

One study ⁽⁴⁴⁾ has found evidence that people taking vitamin C and vitamin E showed a trend towards reduced viral load after three months of treatment, although the result did not reach statistical significance. Allard randomised 49 people with HIV infection to receive either vitamin E (800 IU daily) and 1000 mg vitamin C daily, or a matched placebo. At three months, there was clear evidence of a reduction in the oxidation of body lipids. There was a trend towards a reduction in viral load with a -0.45 log reduction in the supplement group and a half log increase in the placebo group. Nine new infections were reported in the supplement group, versus 7 in the placebo group.

Most of the other evidence that taking supplements of vitamin C can delay progression or improve survival in people with HIV is based on the test-tube studies demonstrating its anti-HIV effects. These studies also suggest that vitamin C's "in vitro" activity against HIV be enhanced when it is used in combination with n-acetyl cysteine (NAC). The researcher who demonstrated vitamin C's anti-HIV effects "in vitro" believes that doses of at least 10 g/day are needed in order to produce the viral inhibition he observed in his laboratory studies. However, high doses of vitamin C cause diarrhoea, a sign that the gut cannot absorb any more of the vitamin. Bowel tolerance varies from one person to another, and is believed to depend upon the ability of the individual to metabolise the vitamin. People with acute illnesses such as PCP are reported to have tolerated doses of 60-150 g/day before the onset of diarrhoea.

Other researchers fear that doses much higher than 10-12g/day may have unforeseeable long-term side effects and that doses higher than this should be used only in the case of an acute infection, and only then under medical supervision. One group found that a 500mg daily supplement of vitamin C might act as a pro-oxidant ⁽⁴⁵⁾, causing cell damage. Another group reviewed data from biochemical, clinical and epidemiological research and found that a dose of 90-100mg vitamin C per day is required to reduce chronic disease in non-smokers. Based on this data, they suggest a recommended daily intake of 120mg vitamin C per day ⁽⁴⁶⁾.

High doses of vitamin C may cause kidney stones due to excess acidity. It is possible to test for susceptibility to kidney stones by doing tests for oxalic acid excretion in urine at different levels of vitamin C use. If oxalic acid excretion increases as the dose increases, an individual is vulnerable, but protection against elevated levels of oxalic acid is provided by taking 50-100 mg of vitamin B6 and a magnesium supplement alongside vitamin C.

Another cautionary note regarding vitamin C is that it promotes the absorption of dietary iron. If you are at risk for iron overload disease (haematochromatosis), do not take vitamin C supplements, or even a multivitamin that contains vitamin C or iron.

A more serious reaction to high doses of vitamin C may be experienced by people who suffer from glucose-6-phosphate dehydrogenase deficiency ⁽⁴⁷⁾. This deficiency is found in about 10 per cent of black Americans and is even more common in Africans and people of Mediterranean and Middle Eastern origin. In one case a man receiving massive doses of vitamin C intravenously suffered a shock reaction in which his red blood cells ruptured. Oral vitamin C is not thought to be capable of triggering such a haemolytic shock.

A group of Finnish researchers reported that vitamin C solution may help herpes lesions to heal ⁽⁴⁸⁾. A solution of 100 mg vitamin C dissolved in 3 ml water was pressed onto herpes sores on the lips using a cotton wool pad three times at 30 minute intervals. Among 46 participants, vitamin C recipients reported significantly faster healing of sores and a reduced rate of scabbing or swelling compared with those given a placebo. However, this trial was conducted among HIV-negative, not HIV-positive, people.

Rather more solidly based than its supposed ability to fight colds is vitamin C's role in preventing heart disease - a topic of increasing interest to ageing PWHIVs who may have high blood lipids.

Vitamin C may have a role in the prevention of heart disease. It may raise levels of the 'good' cholesterol (HDL) and prevent oxidation of the 'bad' cholesterol (LDL) so that it becomes less likely to form thromboses.

One Finnish cohort study ⁽⁴⁹⁾ followed 1605 randomly-selected HIV negative men aged 42-60 for 8½ years. 13.2 per cent of the men who had low blood levels of vitamin C (less than 2mg/litre) had a heart attack during this period. Only 3.8 per cent with normal vitamin C levels had one. Researchers calculated that low vitamin C levels increased the likelihood on having a heart attack 3.5 times.

This research, however, was done on the general population and tells us nothing about whether high vitamin C levels have an additionally protective effect.

A later study ⁽⁵⁰⁾, however, still with HIV negative people, found a clear dose-response rate between high levels of vitamin C and a reduced level of heart disease. Cambridge University researchers measured plasma ascorbic acid concentrations in 19,496 men and women aged 45-79 years and followed them up for four years.

An increase in plasma vitamin C concentration equivalent to a daily 50g increase in intake of fruit or vegetables was associated with a 20 per cent decrease in risk of death from all causes, independent of age, systolic blood pressure, blood cholesterol concentration, smoking, or diabetes.

It was also independent, however, of the use of vitamin C supplements - suggesting that the high plasma levels came from a diet high in fruit and vegetables, and that high levels were not achievable by taking vitamin C pills alone. It is theorised by some researchers that other substances such as the bioflavonoids found in citrus fruit are necessary for the proper absorption and metabolism of vitamin C.

Vitamin C was also associated with a decreased risk of death related to cancer in men.

In a small, early study in Montreal ⁽⁵¹⁾, nine out of 11 patients with ITP "responded" to a supplement of 2g of vitamin C a day by producing increased numbers of platelets. It took some patients as long as 10 weeks to start responding, even though the extra vitamin C was only given for six weeks. Spontaneous recovery from ITP is rare.

A paper in Science Magazine in June 2001⁽¹⁷⁸⁾ was widely reported in the media as indicating that taking high doses of vitamin C, far from helping to prevent cancer, could actually cause it. This is despite one of the paper's authors, Professor Ian Blair of the University of Pennsylvania Centre for Cancer Pharmacology, telling the press: "Absolutely for God's sake don't say that vitamin C causes cancer".

What Blair's team actually found was that, in in vitro experiments, in the absence of transition metal ions (these would be trace elements like iron, copper, chromium, vanadium, manganese etc - see below), vitamin C was able to degrade certain oxidated states of body fats (lipid hydroperoxides) into chemicals that were precursors of a substance called etheno-2'-deoxyadenosine. This is a highly mutagenic chemical which is an analogue of one of the components of DNA and which, if inserted into a DNA molecule, often causes the cell containing it to become cancerous. Blair's cautious conclusion was that this "Could help explain the lack of efficacy [of vitamin C] as a cancer chemoprevention agent". As Science magazine explained, this meant that he was suggesting that the anti-oxidant effects of vitamin C could be neutralised by pro-oxidant effects.

It is important to note that the effects observed by Blair would only operate in situations of trace-metal deficiency and possibly in the absence of other anti-oxidants like vitamin E, where oxidants had already degraded body fat to the hydroperoxide state.

An in vivo equivalent of the dose of vitamin C used by Blair would be about 200mg, suggesting as elsewhere that very high doses of vitamin C could possibly tip the balance of the vitamin's effects towards pro-oxidant rather than anti-oxidant effects. All that can really be said is that the Blair study suggests caution against the use of very high doses: and that his study is contradicted by other studies such as the US National Cancer Institute Study⁽¹⁷⁹⁾ cited above.

There is very little in vivo evidence to suggest that taking high dose vitamin C (over 1g/day) has any protective or immune-boosting effect. All the evidence for doing so is extrapolated from test-tube observations.

However, moderately high doses of vitamin C (c. 150-250mg) do seem to have a protective effect against cardiovascular disease and cancer in the general population, probably due to its antioxidant properties, and there is limited evidence that doses up to 1,000mg/day may help to maintain CD4 counts. There is some evidence, however, that vitamin C is best taken in the form of fresh fruit and vegetables rather than supplements. Vitamins C and E seem to have a synergistic (reinforcing) effect on each other.

The main job of this fat-soluble vitamin, as its name suggests, is to transport calcium - and also phosphorus - around the body. It is responsible for enabling the two elements to form bone, but is also responsible for transporting them out of bone. The typical deficiency disease of vitamin D is rickets - a condition, common in malnourished children and people who do not get enough sunshine, where bones become soft and distorted. It also has a role in calcium transport in the nervous system.

About half the body's supply of vitamin D is synthesised by the action of sunlight on skin, and people such as Muslim women who cover up most of their skin may experience deficiency as a result. Food sources include fish oils, egg yolk, liver, chicken skin, and dairy products and margarine fortified with the vitamin.

Up till recently there has been little indication for the use of vitamin D supplementation in most PWHIVs.

This may change as drug toxicities that affect bone become more apparent and more understood. It is becoming clear that a high proportion of PWHIVs on antiretroviral therapy (of all classes) have an accelerated loss of bone mineral density - though no one yet understands why. In the absence of a causative mechanism, however, HIV experts have done no more than recommend 'adequate' intake of vitamin D, along with calcium, magnesium and weight-bearing exercise.

One theory is that drugs such as protease inhibitors and non-nukes interfere with the liver's ability to process many substances and hormones, including vitamin D, which some researchers consider a hormone. The liver converts vitamin D to its active form so that it can help the body retain calcium.

In laboratory experiments with cells and protease inhibitors, ⁽⁵²⁾ these drugs impaired the conversion of vitamin D between 32 per cent and 80 per cent, depending on the drug tested. This effect of protease inhibitors may reduce the amount of activated or useful vitamin D available for the body. In turn, this reduction in activated vitamin D may decrease the body's ability to retain calcium and build strong bones. These findings need to be confirmed but they underscore the importance of a minimum daily intake of at least 400 international units (10 mcg) of vitamin D per day.

There is limited and conflicting evidence about vitamin D's influence on immunity and HIV. Some research suggests that high levels of vitamin D may actually have an immune suppressive effect and that it may stimulate HIV production. This evidence is based on test tube studies.

On the other hand, the active form of vitamin D has also been shown to stimulate macrophages, white blood cells that combat opportunistic infection such as tuberculosis.

One of the most potent metabolites of vitamin D, 1,25-dihydroxyvitamin D3, is often deficient in people with HIV, especially those with advanced disease. (Metabolites are the 'working chemicals' the body makes from the raw dietary component). Deficiency of this particular vitamin D metabolite is a feature of other immunological disorders, and some experts argue that it is an important part of a fully functioning immune system.

A study ⁽⁵³⁾ compared 54 people with HIV with non-HIV-infected controls. 54 per cent of the HIV-positive group were deficient in 1,25-dihydroxyvitamin D3 in contrast to the control group, who had normal levels. The HIV-infected group had 18 people with undetectable levels of the metabolite and this was associated with advanced HIV-infection, low CD4 count and high blood levels of TNF-alpha. Researchers concluded that the deficiency was possibly induced by an inhibitory effect of TNF-alpha and that low levels of 1,25-dihydroxyvitamin D3 may be associated with the high levels of TNF-alpha that are already known to be a factor in disease pathogenesis, particularly AIDS-related wasting.

Vieth ⁽⁵⁴⁾ reported that a dose of vitamin D of over 100 mcg (4,000 IU) is required to achieve adequate levels of the metabolite in the blood. The toxic dose is over 250mg (10,000 IU).

The idea that the proper metabolism of vitamin D is essential for immune defence was reinforced by another study ⁽⁵⁵⁾ that linked high levels of tuberculosis both with low blood levels of vitamin D and with a gene mutation that leads to fewer receptors for vitamin D on cell surfaces. Over half a group of 242 Asians of Gujarati origin living in London who neither had TB or contact with a TB-infected person, had significantly low levels of hydroxyvitamin D in their blood, and genetic polymorphisms that coded for fewer vitamin D receptors on their cells. People with no detectable hydroxyvitamin D were 10 times more likely to have active TB. The low levels of vitamin D receptor seem to indicate that we are dealing with a genuine vulnerability to TB due to difficulties in vitamin D metabolism, not an effect of TB infection.

Further studies are needed to see if vitamin D receptor mutations convey vulnerability to other diseases such as HIV. Some in vitro studies, for instance, have already suggested that vitamin D is involved in preventing the over-proliferation of cells lining the colon, and that blockages in the metabolic pathway that converts vitamin D to its active form could be a cause of colon cancer.

Vitamin E is a mixture of several different compounds called tocopherols and tocotrienols. An important anti-oxidant and anti-inflammatory, often lacking in HIV-positive people, vitamin E is necessary to ensure the optimum functioning of cell membranes. Its most important function appears to be to prevent the oxidation and degradation of the lipids (fatty molecules) in cell membranes. A large proportion of vitamin E is found in the cell membranes and can attach to free radicals to protect the membrane from oxidation. The resulting tocopheroxy radical can then be recycled by vitamin C to be used again.

This leads to a considerable number of important protective functions. Vitamin E appears to protect against immune system decline, particularly in old people, and boosts levels of certain immune cytokines (messenger chemicals); it protects against atherosclerosis and heart disease, against certain forms of cancer, and against diabetes.

Aids Treatment News in the USA has described vitamin E as "Maybe the most promising of the antioxidants at this point".

Marginal deficiency appears to be quite widespread in healthy adults eating the standard Western diet. Although the main source of vitamin E is vegetable oils, eating a diet very high in unsaturated fats may lead to it leaching out of the system and becoming deficient. Thus health advice to eat large amounts of unsaturated fat, particularly fish oils, in order to protect against heart disease, may be counterproductive.

Until recently the most biologically active form of vitamin E was thought to be alpha-tocopherol, and some supplements contained only this form. More recently (see below) gamma tocopherol has been found to protect better against some cancers. Vitamin E supplements should therefore contain mixed tocopherols.

Vitamin E deficiency may interfere with efficient immune functions, but so may doses above 800 IU a day.

Interest in vitamin E was greatly increased first by an article in the Journal of the American Medical Association that reported on vitamin E supplementation in 88 persons over 65 years old. ⁽⁵⁶⁾. The JAMA authors concluded that vitamin E "enhances certain clinically relevant in vivo indexes of T-cell-mediated function in healthy elderly persons". The trial participants attaining the highest serum vitamin E levels experienced the most improvement.

In vitamin E deficiency most of the immune parameters show a downward trend, which is associated with increased infectious diseases and the incidence of tumours ⁽⁵⁷⁾. In contrast, vitamin E supplementation has various beneficial effects on the host immune system. The decreased cellular immunity with ageing or during the development of AIDS is markedly improved by the intake of a high vitamin E diet. In addition, vitamin E plays an important role in the differentiation of immature T cells in the thymus. Vitamin E deficiency induces the decreased differentiation of immature T cells, which results in the early decrease of cellular immunity with ageing in rats. Conversely, vitamin E supplementation induces a higher differentiation of immature T cells in the thymus, which results in the improvement of decreased cellular immunity in the aged.

Vitamin E supplementation induces the early recovery of thymic atrophy following X-ray irradiation. Taken together, these results suggest that vitamin E is an important nutrient for maintaining the immune system, especially in the aged.

In a study of mice with a murine version of AIDS ⁽⁵⁸⁾, vitamin E supplementation seemed to improve the balance of immune cytokines such as IL-2, interferon gamma (both increased) and tumour necrosis factor (reduced) while increasing immune cell activity. Two other published studies have demonstrated the same results. Vitamin E also reduced NF-kappa B, which can cause injury to the liver by its stimulation of free radicals. In AIDS, NF-kappa B is excessive, as is oxidative stress from free radicals. The same is true for cancer. Vitamin E also reduces the level of lipid oxidation.

Some studies indicate that vitamin E levels are deficient in persons with HIV: University of Miami investigators ⁽⁵⁹⁾ detected low plasma levels of vitamin E in 18 of 100 HIV-positive volunteers, while all HIV-negative homosexual men were found to have adequate plasma vitamin E levels.

In the San Francisco prospective cohort study sited earlier ⁽⁶⁾, Barbara Abrams and her colleagues at UC Berkeley found intake of vitamin E from supplements was significantly associated with a reduced risk of progression to AIDS among 296 HIV-positive men in the San Francisco Men's Health Study. Those whose vitamin E consumption was in the highest third at the study's time zero were about half as likely to develop AIDS as those with lower intake during the following six years.

A study has found people taking vitamins E and C showed a trend towards reduced HIV viral load. ⁽⁴⁴⁾ Allard randomised 49 people with HIV infection to either vitamin 800 IU of vitamin E (alpha tocopherol acetate) and 1000 mg vitamin C daily or a placebo. At 3 months, the supplement group showed signs of a reduction in oxidative damage to body lipids. There was a trend towards a reduction in viral load with a -0.45 log reduction in the supplement group and a half log increase in the placebo group, though this did not reach statistical significance. Nine new infections were reported in the supplement group, versus 7 in the placebo group.

One important study has linked the gradual decline in blood levels of vitamin E with intestinal malabsorption in PWAs due to HIV and parasitical infections. Researchers in the US ⁽⁶⁰⁾ documented a vitamin E deficiency in about 22 per cent of subjects in their study. Others had normal levels, and deficiency was not related to CD4 count. But they also found that in monitoring subjects for one year, vitamin E levels declined by about 40 per cent. No subject was taking more than 10 mg (c. 14 IUs) of vitamin E/day. This important study took place in 1995/96 just as HAART was being introduced, and it is not known to what degree antiretrovirals have reversed or halted this gradual decline in vitamin E levels.

In humans, vitamin E stimulates CD4 cell proliferation at high doses, and in healthy adults has been shown to restore delayed-type skin hypersensitivity reactions and interleukin-2 production at a dose of 400 i.u. per day ⁽⁶¹⁾. It's not known whether this is beneficial at all, or any, stages of HIV infection.

Another study ⁽⁶²⁾ of 310 HIV positive men followed for nine years found that those with serum vitamin E levels above 23.5µm/l had a significantly reduced risk of disease progression. A strong correlation was noted in this cohort between intake of supplements containing vitamin E on entry into the study and high blood levels of vitamin E.

Vitamin E has been shown to improve the anti-viral effect of AZT in the test tube ⁽⁶³⁾, but it has no anti-viral effect on its own. It may also protect the bone marrow cells from damage by AZT.

There are no studies of its specific benefits in HIV-positive people except in the improvement of seborrhoeic dermatitis ⁽⁶⁴⁾. Italian doctors found that HIV-positive people with ARC who took 300-600 i.u. of vitamin E with selenium and methionine saw improvements in seborrhoeic dermatitis and overall white blood cell count.

Recently, scientists at the Johns Hopkins School of Public Health found that higher blood levels of gamma-tocopherol, a form of vitamin E not usually included in vitamin supplements, are associated with a lower risk of developing prostate cancer than alpha-tocopherol, the form of vitamin E most commonly found in supplements. Although seldom studied, gamma-tocopherol is a natural form of vitamin E routinely found in the U.S. diet, notably in soya foods. The study also revealed that high concentrations of gamma-tocopherol appear to boost the prostate cancer-fighting abilities of both alpha-tocopherol and the micronutrient selenium. The study appears in the Dec. 20, 2000 issue of the Journal of the National Cancer Institute.

Median concentrations of both alpha-tocopherol and gamma-tocopherol were lower among the men with prostate cancer than among the control subjects, but these differences were statistically significant only for gamma-tocopherol. Compared with the men with the lowest levels of gamma-tocopherol, men with the highest levels had a fivefold reduction in their risk of developing prostate cancer. What is more, gamma-tocopherol appeared to boost the protective effects of both alpha-tocopherol and selenium. That is, compared with individuals with low concentrations of all three micronutrients, high concentrations of selenium and alpha-tocopherol were associated with a statistically significant decreased risk of prostate cancer only when high concentrations of gamma-tocopherol were also present.

This study suggests that supplementing only with alpha tocopherol may miss out on some of the important anti-oxidant effects of other naturally-occurring forms of vitamin E.

In another recent study ⁽⁶⁵⁾, the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study), 29,133 Finnish male smokers 50-69 years of age were randomly assigned to receive a 50-mg daily dose of vitamin E (as alpha-tocopherol), a 20-mg daily dose of beta carotene, both supplements, or a placebo. The latest analysis of the study found that the men who received the daily dose of 50 mg of vitamin E for 5 to 8 years (median 6.1 years) had one third fewer prostate cancer diagnoses and 41 per cent fewer prostate cancer deaths compared with men who did not receive vitamin E. The addition of the beta carotene slightly improved the prostate cancer figures, but this was outweighed by it apparently increasing the risk of lung cancer.

Vitamin E supplements can substantially cut the risk of heart disease, and may even reverse atherosclerosis (hardening of the arteries) which is its main cause.

The mid-90s studies which showed this are just about the only large controlled studies which show a beneficial effect on health in the general population of taking a vitamin considerably in excess of the amount available in a normal diet, or the current RDA. There is strong scientific evidence of positive benefit, not only for those who are sick but even in healthy persons with good diets.

In three large studies ⁽⁶⁶⁾, each including more than 20,000 persons, individuals taking only 100 units of vitamin E daily cut their risk of coronary heart disease almost in half (37 percent to 43 percent). Furthermore, in a fourth study, carried out in 2,000 persons with underlying coronary artery disease, vitamin E supplementation of 400 IU or 800 IU daily for one and a half years resulted in a much improved survival rate compared to study participants who did not take vitamin E supplementation. Another study of 162 patients showed that vitamin E slows, may even reverse, atherosclerosis.

The patients studied were part of the USC Cholesterol Lowering Atherosclerosis Study (CLAS). CLAS investigators evaluated the narrowing in blood vessels of 162 non-smoking men aged 40 to 59 years. They were then randomly selected to take vitamin E with either a placebo or the drug colestipol along with high doses of niacin (which was already known to reduce cholesterol, see ref. 23 above) at the beginning of the study and again after two years. CLAS subjects also reported their intake of supplemental vitamins.

Those taking 100 IUs (c.71mg) per day or more of vitamin E showed significantly reduced narrowing of their arteries. Changes in blood vessel narrowing were measured using angiograms - x-rays of the arteries, a completely objective method.

Vessel narrowing appeared to slow regardless of whether patients were taking the vitamin E and placebo or vitamin E and the cholesterol-lowering regimen.

More recently, the Cambridge heart antioxidant study (CHAOS)⁽⁶⁷⁾ showed a 77 per cent reduction in non-fatal myocardial infarction in patients with angiographically proved coronary heart disease who took 400 or 800 IU of vitamin E daily.

A study in January 2000⁽¹⁸⁰⁾ published in the New England Journal of Medicine failed to find a protective effect of vitamin E against heart disease. The investigators enrolled a total of 2545 women and 6996 men aged 55 years or older who were at high risk for cardiovascular events because they had cardiovascular disease or diabetes in addition to one other risk factor. These patients were randomly divided into four groups which received either 400 IU of vitamin E daily from natural sources or matching placebo and either ramipril, a drug that helps to prevent blood-vessel constriction, or matching placebo. So a quarter of the patients either had both vitamin E and ramipril, only vitamin E, only ramipril, or neither. The study took place over 4.5 years.

The study reported that vitamin E had no significant difference on the risk of developing heart disease within the study period (in fact five per cent more of the patients on vitamin E developed heart disease, a non-significant difference).

Vitamin E concentrations are reduced in some patients with diabetes and oxidative stress is enhanced. And since both raised blood triglycerides (which have been shown to increase atherosclerosis) and diabetes are side effects of protease inhibitor drugs ⁽⁶⁸⁾, dietary supplementation with vitamin E is a logical approach to reducing the incidence of complications associated with diabetes and raised triglycerides in PWHIVs.

In one Finnish study ⁽⁶⁹⁾, there was a strong independent association between low vitamin E status and an excess risk of diabetes at four years, supporting the theory that oxidative stress has a role in the causation of non-insulin dependent diabetes. Patients with below average vitamin E blood levels had a 3.9 times greater risk of developing diabetes than patients with above average levels.

Many minerals are as vital to life as the vitamins. The body uses a surprising array of different metals and non-metallic elements to perform various functions. The amounts needed vary from elements like calcium, potassium and phosphorus which form quite large parts of the body's structure, to elements only needed in microscopic amounts like iodine, selenium and chromium. Many enzymes, hormones and even vitamins incorporate heavy elements into their structure, such as selenium in the enzyme glutathione peroxidase, zinc in numerous enzymes, iodine in thyroid hormone, cobalt in vitamin B12 and of course iron in haemoglobin, the oxygen-carrying red pigment in blood. Sodium, potassium and calcium between them make it possible for the nerves to carry electrical signals. Calcium and phosphorus form the mineral component of bones.

The biochemistry of the rarer trace elements is still little understood. Even elements like vanadium, silicon and the deadly poison arsenic seem to have minor roles to play in body chemistry. Here we will deal only with ones directly investigated for their role in immunity and HIV disease.

The most abundant metallic element in the body, calcium is well known to be the most important bone-forming mineral, but it is also involved in many other bodily processes, including having a vital role in the nervous system and in the transport of substances, including neurotransmitters, across cell membranes. In fact it is so vital for life that the body quite tightly controls its calcium intake, and it is difficult to over- or under-dose. Calcium deficiency is mainly seen in situations of sudden loss, as in pre-eclampsia, a condition where nursing mothers and animals have fits due to the loss of calcium in breast milk not being made up by diet.

The body gradually loses bone calcium after middle age to a greater or lesser degree, and this is well-known to be a problem particularly for post-menopausal women, who are recommended to approximately double their pre-menopause RDA of 800 grams.

Core foods for calcium include milk and dairy products, shellfish and fish containing bones such as tinned salmon and sardines. For vegans, who have to be careful about getting enough, some crunchy green vegetables such as kale and seaweed also contain significant amounts.

Calcium supplements need to be in a form that the body can absorb; it is no use just chewing chalk, and some 'calcium-fortified' foods actually supply little extra.

An increased calcium intake also needs to be balanced with magnesium, as the two minerals regulate each other's levels in the body. See table above for recommended amounts.

There is also a relationship between calcium and phosphorus. For optimal absorption of each, the relationship should be one to one. Too much phosphorus causes poor absorption of calcium. In a study that compared female athletes who drank carbonated soft drinks -many of which contain phosphoric acid -- with those who did not, those who drank the soda had more bone fractures. If you are concerned about calcium loss, you should restrict your intake of soft drinks and other foods that contain phosphoric acid.

A recent worrying development in anti-HIV treatment is bone mineral loss, a condition called osteopenia when moderate, or osteoporosis when severe and accompanied by obvious changes in structure and strength. Researchers in Western Australia ⁽⁷⁰⁾ studied the impact of anti-HIV therapy on the bones of 171 male PWAs. The research team found that an surprisingly high proportion of subjects - nearly 50 per cent- were losing significant amounts of calcium from their bones. 17 per cent of subjects had osteoporosis. Both of these groups of subjects were using protease inhibitors. Interestingly, the investigators found that the use of indinavir, unlike the other PIs, was associated with an increase in bone mineral density.

In another experiment ⁽⁷¹⁾, researchers studied 73 HIV-positive subjects receiving combination anti-HIV therapy that included a protease inhibitor. After analysing urine samples, researchers found that 50 per cent of subjects were losing more than 200 mg of calcium each day. It is theorised that some PWAs are developing osteoporosis because their bodies are unable to retain the calcium absorbed from their diet.

The most common and probably most annoying side effect of nelfinavir (and often other protease inhibitors) is diarrhoea. In a small study ⁽⁷²⁾ involving 24 patients, calcium supplements reduced nelfinavir-induced diarrhoea in as little as 48 hours.

Before taking part in this study, 50 per cent of the patients reported their diarrhoea as mild (grade one, one to three loose stools per day), 42 per cent described it as moderate (grade two, three to seven loose stools per day), and eight per cent rated it as severe (grade three, more than seven loose stools per day). All patients had been taking at least one anti-diarrhoea drug.

The subjects were given 500 mg of calcium twice a day and were asked to report any changes in bowel activity after a minimum of 48 hours. All 24 patients reported improvement, with 16 (67 per cent) reporting normal stools and eight (33 per cent) mild diarrhoea.

A report in Aids Treatment News ⁽³⁰⁾ says that a simple regimen of calcium, magnesium and vitamin B6 has been used to protect the nerves or treat peripheral neuropathy.

Dr Jon Kaiser, author of Healing HIV, recommends taking calcium 500mg, magnesium 250mg and vitamin B6 100mg twice a day, particularly for people taking d4T. If neuropathy is present, he recommends doubling the dose of B6. Another San Francisco doctor, Virginia Cafaro, recommends 1000mg calcium and 500mg magnesium twice a day, but only 100mg of B6 once a day, combined with acupuncture.

Chromium is mainly involved in the metabolism of glucose. A number of studies have shown that chromium stimulates insulin action in the body. However, the daily requirement for chromium could not be established because not enough information exists to determine a relationship between a particular dose of the nutrient and insulin response. Not all studies show that chromium supplementation has a positive effect on the regulation of glucose levels. More than 1000mcg/day causes toxicity. Lean meat, eggs and brewer's yeast are rich sources of chromium.

Chromium appears to act in concert with the element vanadium, but even less is known about this mineral's action. An average diet provides about 15-30 mcg of vanadium. Nuts and beans are particularly rich in vanadium.

The main function of this mineral seems to be in preserving the strength and flexibility of blood vessels. It does this indirectly by assisting, along with zinc and the enzyme superoxide dismutase, in the regulation of nitric oxide (NO), a molecule that regulates the contraction of the smooth muscles lining blood vessels and other vessels. The degradation of NO by superoxide (O₂-) free radicals occurs during copper deprivation. Copper deficiency in rats leads to leaky blood vessels, poor circulation, an increased sensitivity to the allergy-causing chemical histamine and the loss of other minerals ⁽⁷³⁾.

It has been hypothesised ⁽⁷⁴⁾ that zinc and copper ions stimulate/inhibit/block in a concentration-dependent way the (intracellular) activation of essential HIV proteases. Zinc and copper ions thus act as 'passive' HIV protease inhibitors.

Sources of copper in food include seafood, liver, cocoa, nuts and dark green vegetables. High doses (over 10mg or 11 times the RDA) interfere with zinc absorption.

Iron is essential for the formation and function of red blood cells. Vitamin C promotes the absorption of iron.

Anaemia is the iron deficiency disease, but the anaemia associated with HIV is not necessarily caused by inadequate iron.

An oversupply of iron in HIV is potentially harmful. Excess iron can deposit in the liver and the heart. When oversupplied, iron can stimulate free radical production and further damage the immune system. In one study, iron levels were higher in people with HIV.

Men's vitamin formulations are already omitting iron because of problems associated with men's health, including heart disease and colon cancer. Vitamin-mineral formulations made for adults over 50 years of age are low or lacking entirely in iron because of these findings. In the early 1940s there was a campaign to fortify food with iron to combat the high incidence of iron deficiency anaemia. This did not solve the problem, and because of the new problems associated with excess iron and disease there is a move to discontinue the practice.

Women, on the other hand, need extra iron until they pass menopause, and particularly during pregnancy and lactation. Women's formulations still have iron because of the significant monthly blood loss associated with menstruation.

People who have the iron accumulation condition haematomachrosis should avoid both iron and vitamin C supplements.

Needed for energy production and protein synthesis, magnesium is found in whole grains, legumes, leafy green vegetables, nuts, and chocolate. Deficiencies can cause muscle spasms, tremor, convulsions, and mental derangement.

Calcium and magnesium, which are chemically similar, tend to form a state of homeostasis (balance) in the body, and supplementation by one may lead to depletion of the other. For this reason they should always be taken together, if at all.

Stress, a common condition in people with HIV, can deplete the body's stores of magnesium. The anti-PCP drug Septrin (co-trimoxazole, Bactrim) interferes with magnesium absorption. Diarrhoea increases magnesium losses, and alcohol decreases absorption. If you think your diet and your multivitamin together do not provide the recommended 280 to 350 mg per day, you need to supplement.

Jon Kaiser, a holistic AIDS doctor from San Francisco, recommends adding magnesium to your regimen along with calcium and vitamin B6 for the management of peripheral neuropathy.

This mineral is not toxic, and unlike calcium it is not given up by the bones for all the functions it has to perform. When you are not getting it from food and supplements, you risk a deficiency state.

Hardly a 'trace element', potassium is the second most abundant metallic element in the body after calcium. With sodium, calcium and chloride, it enables nerve impulse transmission, muscle contractions, regulates heartbeat and blood pressure, and is required for the proper function of protein, carbohydrates, and insulin secretion.

About two grams a day are needed. Potassium is abundant in raw vegetables and fruit, particularly orange and yellow ones (bananas are a good source), potatoes and lean meat.

Because it acts as an antagonist to sodium - which is nearly always in over-supply in Western diets - potassium may help protect against strokes and high blood pressure, in which an excess of sodium is thought to be a causative factor.

Deficiency can occur suddenly or chronically as a result of diarrhoea. The severe weakness caused by a bout of diarrhoea is mainly due to low potassium (and glucose) levels in the muscles. Have a banana - they are full of the soluble fibre that helps to control diarrhoea too.

Drugs such as diuretics, which are given to people with fluid accumulation due to heart or lymphatic problems, also cause the body to lose potassium, and it should be supplemented.

Although this element is only needed in trace amounts, it is important in HIV infection because of its role in the metabolism of the essential anti-oxidant glutathione. Selenium works in concert with vitamin E as an antioxidant.

In the UK the Ministry of Agriculture (MAFF)⁽⁷⁵⁾ recently recommended that cereals and flour should be fortified with selenium. UK intakes of selenium have fallen since the 1970s (based on analyses on samples by MAFF). This is thought to be due in part to the trend over the past 25 years towards using selenium-poor European wheat rather than selenium-rich North American wheat for bread making. Some northern European countries like Finland are so selenium-deficient that it is added to fertiliser. Additionally the overall consumption of cereal foods, most notably bread, has declined in the last 20 years.

Although the main source of selenium is wholemeal grains, it is also found in mushrooms and yeasts, nuts (especially Brazil nuts - one nut contains 100mcg of selenium), cashews, garlic, eggs and seafood.

Selenium is only needed in microgram amounts, and cautious nutritionists recommend a regular supplement of no more than 250mcg/day (five times the EU RDA) and a total intake from all sources of 400mcg. Selenium taken in excess (over 1,000mcg a day regularly) may be immunosuppressive and result in toxicity, with symptoms including loss of hair and nails, skin lesions, nervous system disorders, vomiting and diarrhoea. L-selenomethionine is absorbed more efficiently than inorganic selenium and is a less toxic form of the mineral.

Glutathione and selenium combine to make up glutathione peroxidase. Glutathione is an antioxidant that seems to play a role in HIV management - see the section on n-acetyl cysteine (NAC) for more details. It appears to be the major intracellular antioxidant. Glutathione is a peptide made in the liver from three amino acids - glycine, cysteine and glutamic acid. Riboflavin (vitamin B2) is needed for its synthesis and the selenium-containing peroxidase enables the glutathione to do its job of scavenging harmful oxygen radicals. According to a group of researchers from California, a decrease in glutathione levels accelerates the destruction of T-cells and mortality from AIDS. Glutathione also helps the liver to detoxify, protects red blood cells from damage and the eyes from cataracts.

Selenium is involved in many other processes in the body, some still obscure. A review of its properties was published in The Lancet last year ⁽⁷⁶⁾. The author, Margaret Hayman, notes that supplementation with selenium, even in individuals that appear to get enough, has marked immunostimulant effects, including an enhancement of proliferation of activated T-cells. Lymphocytes from volunteers supplemented with selenium at 200 micrograms per day showed an enhanced response to antigen stimulation and a 118 per cent increased ability to develop into cytotoxic lymphocytes and to destroy tumour cells. Natural-killer-cell activity was also increased.

The researchers found that very low levels of certain nutrients--vitamins A, B12, selenium, zinc and protein - were all associated with reduced survival compared to others who did not have such low levels of nutrients. This difference was statistically significant; that is, not likely due to chance alone. However the researchers found that selenium status was by far the best able to predict survival or death.

The study that reported these surprising findings took place before the HAART era, and the only antiretroviral any patients were taking was AZT. There has not been an equivalent study since to see if selenium levels predict morbidity or mortality in people taking combination therapy.

A study presented at the Durban AIDS conference ⁽⁷⁸⁾ reported finding selenium deficiency in 11 per cent of 318 women studied in Kenya. They found that the deficiency was associated with a nearly 3-fold increased likelihood of shedding of genital mucosal HIV-1 DNA, suggesting that deficiency may increase the infectiousness of women with HIV-1.

Mary Romeyn, an HIV doctor in California, also suggests a link between selenium levels and genital health, reporting thrush (Candida) clearance in women given selenium supplements.

Selenium also appears to be protective in individuals infected with hepatitis B or C against progression to liver cancer. Various studies have found more cancer or cancer deaths in persons with low selenium levels. For example, Hayman reports that in a prospectively followed cohort of 34,000 men, those in the lowest 20 per cent of selenium status, as measured by toenail selenium, were found to have three times the likelihood of developing advanced prostate cancer as those in the highest quintile (p for trend=0.03). Only cases diagnosed more than two years after collection of the samples were counted, so as to avoid confusion due to the possibility that the illness itself might cause the low selenium levels.

Zinc deficiency can result in loss of taste and smell acuity, slow wound healing, fatigue, increased susceptibility to infection, and recurrent viral infections. Testosterone levels can also drop as a result of zinc deficiency. Diarrhoea may cause zinc loss.

Zinc, unlike vitamin C, actually does appear to cure colds. In one study ⁽²⁾, over-the-counter zinc lozenges bought less than 24 hours after the start of a cold made the symptoms disappear in an average of 4.4 instead of 7.6 days.

Food sources of zinc include brewer's yeast, egg yolks, fish, lamb, legumes, meat, pumpkin and sunflower seeds, and whole grains.

One group ⁽⁸⁰⁾ found a higher percentage of HIV-positive homosexual men to have low plasma zinc levels in contrast to HIV-negative homosexual men. A number of studies using small patient populations have demonstrated modest improvements in lymphocyte counts, CD4/CD8 ratios, body weight and quality of life.

This observation has always been controversial, and seems to be contradicted by some of the smaller studies. But if it is accurate and still holds in the post-HAART era, the reason may lie in the essential functions zinc performs in HIV's lifecycle (involving the packaging of genetic material in new virions and, later on, the integration of HIV genes into those of uninfected cells.) Further research is needed to establish the optimum levels of zinc in individuals infected by the virus. But for the time being, people should not take more than 15mg of elemental zinc a day (which may be more in terms of milligrams if measured as the actual chemical form taken, e.g. zinc citrate, picolinate or amino acid chelate).

Vitamins and minerals are by no means the only supplements used by PWHIVs. A large array of different substances have been used both in an attempt to moderate HIV disease and, since the advent of HAART, to control side effects. Many are either antioxidants, substances which, by donating electrons to them, neutralise the dangerous effects of free oxygen radicals in the body (see above), or which interfere directly in biochemical events which allow HIV to reproduce. Others moderate drug side effects or are used to control the effects of opportunistic infections.

There is no room here to include more than the most commonly-used and studied ones. Specifically herbal extracts - as opposed to chemicals isolated from herbs, like bioflavonoids - will be found in the separate section on herbs.

Alpha lipoic acid (ALA) or thioctic acid is a sulphur-containing compound, which acts as an important antioxidant. Being both lipid (fat) and water-soluble, it readily crosses cell membranes and can repair oxidative damage inside cells. It neutralises the effects of many different substances containing reactive oxygen, including hydroxyl (OH-) radicals, the most damaging of all.

It acts in synergy with other anti-oxidants, reducing their depletion. It helps, in concert with vitamin C, to recycle vitamin E back from its oxidised to its reduced (non-oxidised) form, and has been shown in animal studies to protect against the symptoms of vitamin C and E deficiency in animals fed deficient diets.

In one small study of ten people with AIDS (CDC stage four) ⁽⁸¹⁾ supplementation with 600mg of ALA a day significantly increased plasma vitamin C levels in nine participants, glutathione levels in seven, and produced a non-significant increase in CD4 counts.

ALA also appears to have a direct effect on HIV replication. In order to reproduce HIV depends on 'hijacking' a number of gene transcription factors that are present in cells, including in particular the protein nuclear-factor kappa-B (NFkB). Without NFkB expression, HIV cannot reproduce. NFkB also increases the level of cytokines, which cause increased CD4 cell production and immune overstimulation. In a study by the same investigators as the previous one, an HIV-infected human T-cell line was treated with ALA. Complete inhibition of NF-kB activation was reported using approximately two-thirds of the dose used in clinical practice, and a quarter of that needed to produce the same effect with N-acetyl cysteine.

A number of substances, including he common anti-inflammatory drugs aspirin and indomethacin, have been shown to reduce NFkB expression. ALA appears to work by dampening down the free oxygen radicals which stimulate the production of NFkB, thereby inhibiting HIV replication. In one in vitro study, ⁽⁸²⁾ using 0.2 milliMols ALA reduced the expression of HIV genes by 40 per cent in an infected cell line, and worked better than the other popular anti-oxidant N-acetyl cysteine (NAC). In an earlier one by the same investigators, ⁽⁸³⁾ complete inhibition of NF-kB activation was reported using approximately two-thirds of the dose used in clinical practice, and a quarter of that needed to produce the same effect with N-acetyl cysteine.

In an early German study ⁽⁸⁴⁾ ALA was shown to inhibit the infectivity of virus particles and thus suppress HIV replication in vitro, and a follow-up in vivo study ⁽⁸⁵⁾ showed significantly reduced viral loads.

It is a good idea to take ALA if you also take NAC anyway: it is possible that taking too much cysteine may cause nerve damage if the inflammatory cytokine tumor necrosis factor (TNF) is also present: ALA has been shown to damp down the effects of TNF. TNF is one factor that is associated with Aids-related wasting; though I have been unable to find any trial that investigates whether ALA can help with this.

Another important function may be in protecting liver cells from the effects of antiretrovirals and other substances. It has long been used to protect the liver in Europe in cases of mushroom poisoning, alcohol-induced hepatitis and even radiation sickness. It may help reduce damage to healthy cells during cancer chemotherapy, and when taken together with milk thistle (silymarin) has been shown anecdotally to reduce levels of elevated liver enzymes.

ALA has also been used in Europe for a long time to treat the peripheral neuropathy common in diabetes. A number of clinical trials have shown its usefulness in controlling neuropathy pain, and it is licensed in Germany for this use. One 1993 study showed a reduction in oxidative stress in diabetics given either ALA, selenium or vitamin E - each substance seemed to work equally well.

The few studies done of ALA in PWHIVs have used doses of either 300mg or 600mg/day, usually in three doses taken at meal times. In studies with HIV negative volunteers, decreased blood platelets (thrombocytopenia) and nausea were reported by those taking 900mg a day or more. ALA is also a chelating agent - it removes minerals from the body, and in another study with HIV negative volunteers, ALA use was shown significantly to reduce blood iron levels.

ALA is quite expensive, at £15-25 for a month's supply if 300mg/day are taken. DAAIR recommend a 'maintenance dose' of 100mg once a day.

This is a whole family of chemicals found in various different plants and particularly in fruits and vegetables. Some are pigments, responsible for the bright red, yellow, blue and purple colours of certain fruit and flowers - hence their other name of anthocyanins, which simply means substances that make flowers blue. Common sources include brassica vegetables such as red cabbage and broccoli, green tea, purple berries such as black cherries and grapes, blackberries and blueberries, and red wine. Consuming the latter is one of the explanations suggested for the so-called 'French paradox' - the tendency of this nation to have a low incidence of heart trouble despite high levels of cholesterol and saturated fats in the diet.

Other herbs such as species of pine and chrysanthemum, Rhus (sumach) and Berberis (barberry) have bark, berries and flowers particularly high in bioflavonoids.

Bioflavonoids have been shown to prevent low-density lipoprotein ('bad' cholesterol) from oxidising and thereby forming insoluble plaques within arteries, to promote the synthesis of protective fatty acids such as eicosapentaenoic acid, to prevent platelets (the blood-clotting cells) clumping together to form thromboses, and to promote relaxation of cardiac muscle. Their anti-oxidant properties have also led to them being seen as the reason why diets high in fruit and vegetables seem to protect against certain cancers. Some bioflavonoids seem to have directly anti-tumor effects. ⁽⁸⁶⁾

However, many bioflavonoids are not very bioavailable (do not cross from the digestive tract to the bloodstream easily) and are degraded by digestive enzymes. Measurements of plasma levels of the most intensively studied bioflavonoid, quercetin, show that the plasma levels it reaches could not account for the 'French paradox'. ⁽⁸⁷⁾

Apart from their cardiovascular effects, bioflavonoids may be of use to PWHIVs because many exhibit considerable ability to inhibit the reverse transcriptase (RT) enzyme and may therefore inhibit HIV replication. One study ⁽⁸⁸⁾ evaluated the in vitro anti-HIV activity of 10 different bioflavonoids isolated from the Rhus and Garcinia plants and found that one, morelloflavonone, reduced HIV replication by 50 per cent at a plasma concentration of 6.9 microMols. Others did the same at greater concentrations. One 1993 study ⁽⁸⁹⁾ found that although quercetin showed no anti-HIV activity, a closely similar compound called myricetin reduced HIV infectivity by acting as a fusion inhibitor, blocking the gp120 HIV envelope protein from attaching to cells, as did several similar compounds. They also showed a similar ability to block herpes simplex virus surface proteins. However, the authors' comment that "These naturally occurring compounds merit further investigation as good candidates for the inhibition of sexual transmission of HIV infection" appear to have gone unheeded.

One 1996 study looked at pycnogenol ⁽⁹⁰⁾, a commercial mixture of bioflavonoids manufactured from pine bark and sold as an anti-oxidant. They fed the supplement to mice whose immune systems were stressed either by infecting them with a mouse immunodeficiency virus or by feeding them high levels of alcohol. As well as pycnogenol increasing natural killer cell activity, it also increased the levels of the cytokine interleukin-2 (IL-2), which stimulates CD4 and CD8 cell production. It also decreased elevated levels of the cytokines IL-6 and IL-10, which are characteristic of the other Th-2 type of immune response which is thought to speed progression to AIDS in humans.

Pycnogenol is quite expensive, at around £20 for a month's supply as Solgar's recommended dose of 150mg/day. Mixed bioflavonoids derived from citrus fruit are much cheaper.

Other common plant chemicals - many of which are also brightly coloured - include: -

• The orange and yellow carotenes (see vitamin A above)

• Lycopene, the red chemical found in tomatoes, pink grapefruit, watermelon and guavas, which several studies have associated with decreased rates of prostate and other cancers (tomatoes need to be cooked to release the chemically active form)
• Lutein, a bight yellowish-green chemical found in spinach and other green leafy vegetables, which has been shown to protect against blindness caused by macular degeneration
• Allyl sulphides - the uncoloured but pungent chemicals that give garlic, onions and other Alliums their smell. One of these, allicin, has been used as a popular alternative remedy for cryptosporidium and other intestinal parasites, is strongly associated with lowered cholesterol and risk of thrombosis, and weakly with a reduction in the rate of certain cancers.

More on these in the 'Herbs' section.

First isolated in cow heart cells, Co-Enzyme Q-10 (Co-Q10 or ubiquinone) is a naturally occurring nutrient found in mammalian tissue, primarily in the heart, liver kidney and muscle. It helps regulate the energy production and energy utilisation of the mitochondria, which is vital to good function of cells and particularly muscle cells. Co-Q10 levels are particularly low in people with congestive heart failure, HIV infection, muscular dystrophy, severe gum disease, and in people treated with certain cancer chemotherapies such as doxorubicin. A small early study ⁽⁹¹⁾ involving only seven patients reported improved CD4:CD8 ratios in people treated with 200mg of Co-Q10 a day.

Supplementation with Co-Q0 is believed to help maintain adequate levels of this nutrient in the body, promoting good mitochondrial and cellular function. A possible outcome of this may be a reduction in the symptoms of drug or disease-induced mitochondrial toxicities being experienced by people with HIV. Co-Q10 has been used since 1985 as a supplement for people with cardiomyopathy, failure of the heart muscle ⁽⁹²⁾, and for people recovering from heart surgery. Cardiomyopathy is an uncommon side effect associated with AZT, but other myopathies are more common with this drug, and Co-Q10 supplementation may help people taking AZT avoid muscle pain and wasting.

Co-Q10 is available without a prescription at most health food stores. All the research on Co-Q10 strongly recommends the "soft-gel capsules." Absorption using the soft-gel capsules is reported to be in the 60-80 per cent range. Powder capsules are also available, but absorption is reported to be much lower, in the 15-20 per cent range. No toxicity has ever been reported with Co-Q 10, and famed nutritionist and physician Dr. Andrew Weil reports that he takes 100 milligrams once a day as a general health booster. The cost of Co-Q10 is relatively high compared to other supplements: a 60-day supply (at 100mg/day) costs £30.75 (without any buyers' club discount) from specialist shops like the Nutri Centre.

One of the most controversial substances used as a form of self-medication by some people with HIV, DHEA is a natural hormone secreted by the adrenal gland. It is the most abundant hormone in the body, and a precursor (building block) of several human hormones including the male sex hormone testosterone and the female sex hormone oestrogen. DHEA reaches peak levels in the blood around during early adulthood, then gradually declines.

Due to its chemical structure, DHEA belongs to the class of drugs known as steroids. It may be taken to supplement the body's own production of steroid hormones but DHEA is not a muscle building (anabolic) steroid. DHEA has been studied as a potential treatment for many conditions including cancer, diabetes, obesity, ageing and diseases affecting the immune system.

DHEA is a prescription-only drug in the EU. It is licensed in Italy and Japan for the treatment of menopause and depression. It is, however, available from the USA through buyers' clubs such as DAAIR, although there have been reports that the US Food and Drug Administration may soon move to restrict sales of DHEA.

DHEA is also known by its full chemical name dehydroepiandrosterone or dehydroisoandrosterone, or the trade name "EL-10". It is metabolised in the body into DHEA sulphite, DHEA-S, which is also sometimes available from buyers' clubs.

Natural DHEA levels tend to decline in people with HIV as the disease progresses. This may indicate that DHEA inhibits HIV, or simply reflect that HIV damages the adrenal gland.

It has been suggested that the under-production of DHEA in people with AIDS may be a cause of wasting, but a pilot study of DHEA in people with AIDS found no consistent effect on their weight. Some studies suggest that, like anabolic steroids, it increases muscle and reduces fat, although other studies disagree.

Most recently, low DHEA levels have been observed in men with HAART-related lipodystrophy. This has led to the theory that lipodystrophy may be caused by hormonal abnormalities due to HIV. During untreated HIV infection the ratio of DHEA to the hormone cortisol, which acts as an antagonist to DHEA, becomes lower. Treatment with HAART goes some way to restoring DHEA levels but cortisol levels remain too high. Since the balance of hormones in the body is as important as the levels of single ones, it is theorised that DHEA supplementation may prevent some of the damaging effects of cortisol, whose lipolytic (fat-dissolving) effects are seen as a possible contributing factor to lipodystrophy.

Test-tube studies ⁽⁹³⁾ have found that DHEA has a moderate anti-HIV effect and may inhibit HIV infection of macrophages or HIV production from infected macrophages.

DHEA stimulates the production of the cytokine interleukin-2, which is required for the production and functioning of CD4 cells. A low level of DHEA may inhibit the production of IL-2, contributing to depressed levels of CD4 cells. It has been suggested that DHEA treatment may have the same effect as treatment with IL-2 ⁽⁹⁴⁾. This theory has not been tested.

Tests in animals indicate that DHEA may act as an immune modulator, by restraining autoimmune responses. DHEA appears able to 'reset' the immune system to the Th-1 type of immunity, characterised by high levels of lymphocyte-stimulating cytokines like IL-2, and away from the Th-2 type which predominates in AIDS, and which is characterised by high levels of inflammatory and cell-killing cytokines like Tumour Necrosis Factor. Various artificial analogues of DHEA like HE-2000 and Anticort are currently undergoing trials as anti-AIDS drugs. DHEA is currently being tested for the treatment of the auto-immune disease lupus in humans ⁽⁹⁴⁾, following research which showed that DHEA treatment stabilised or improved the condition, whilst those receiving a placebo suffered worsening lupus.

DHEA is an unlicensed, experimental drug. Clinical trials have failed to show any benefits so far, but further studies with higher doses are under way.

Anecdotal reports from doctors who have used DHEA widely in their clinical practice suggest that DHEA seems to have more effect on symptoms such as fatigue, depression and chronic malaise than on markers such as viral load or CD4 count. Nevertheless, a study in Texas suggested that DHEA reduced the viral load of people with CD4 counts between 50 and 300.

If you are considering trying DHEA, consult your doctor. Your natural DHEA levels should be measured before commencing supplements. Some people with high CD4 counts may actually have increased DHEA levels. The idea is to restore DHEA levels to normal, not to boost them to supranormal levels.

The most frequent side effect of DHEA is acne, which is particularly common among women. Irregular heart beat and heart palpitations have also been reported among individuals on DHEA. One test-tube study found that DHEA was antagonistic to AZT, i.e. it lessens the drug's anti-HIV effects. However, the manufacturer reports that its in vitro tests showed that DHEA and AZT are synergistic.

DAAIR warns that high doses may increase the risk of side effects. Instead, doses between 2-15 mg are recommended every second day, or for two or three weeks out of every month.

Because DHEA may increase the level of IL-2, which in turn increases CD4 counts, it may theoretically increase viral load (as may IL-2 itself), especially in patients not taking antiretrovirals, taking suboptimal regimens, or ones to which they have become resistant. It is therefore probably best combined with a successful HAART regimen.

People with Kaposi's sarcoma or hormonally driven cancers such as breast, testicular and prostate cancer, should not take DHEA.

DHEA is available in the United States, but is a controlled substance in the UK. Mail order of this substance from the United States does not appear to be illegal, and an internet search will turn up a vast array of suppliers, although quality may vary. In one US quality-control study ⁽⁵⁾ only seven of 16 products were found to have DHEA content within 90-110 per cent of the labelled claim. No DHEA was found in one supplement, only trace amounts in two others - while in one other, 50 per cent more DHEA was present than claimed.

Henderson ⁽⁹⁹⁾ reported that treatment with DHEA or its novel synthetic analogues 8354 or OH8356 resulted in a modest down-regulation of HIV-1 replication in stimulated peripheral blood lymphocytes as measured by syncytia formation, release of p24 antigen and accumulation of reverse transcriptase activity.

Dyner ⁽¹⁰⁰⁾ enrolled 31 HIV-positive asymptomatic individuals (CD4 cell count range 250-600) in an open-label dose-ranging trial of DHEA (three times daily in doses ranging from 750 mg/day to 2250 mg/day for 16 weeks). The drug was well tolerated and no dose-limiting side effects were noted. Dose proportionality was not evidenced by the serum DHEA time-concentration curves for the three dosing groups. However, the study cohort appeared to consist of two subpopulations with markedly different bioavailability for a given DHEA dose. Neither sustained improvements in CD4 counts nor decreases in serum p24 antigen or beta₂-microglobulin levels were observed.

Salvato ⁽¹⁰¹⁾ treated 20 adults with CD4 counts between 50 and 300 with DHEA (300 mg or 600 mg twice daily). After 28 days, the 600 mg dose group had experienced a 1 log reduction in plasma viral load and a greater than 1 log reduction in PBMC viral culture.

At the Community Research Initiative (CRI) in New York, 10 people with AIDS completed a 16-week phase I toxicity study of DHEA (1 g by mouth once daily). Neither side effects nor clinical improvement were observed.

Glutamine is an amino acid, one of the 'building blocks' of proteins, and is in fact the most abundant amino acid in animal tissue.

Glutamine is particularly abundant in immune cells, muscles and the lining of the intestines. When the body is under stress such as vigorous exercise, muscle tissue releases glutamine to meet immediate demands in other parts of the body. It is theorised that during HIV infection, the muscles and intestinal lining become chronically glutamine-deficient as it is 'shunted' to the immune cells to enable their greater rate of activation. The body needs about 7-8 grams of glutamine a day even in normal circumstances, and some nutritionists believe that the body's need for glutamine may exceed its ability to produce it when the body is chronically stressed. A study presented at the 1989 world Aids conference suggested that glutamine levels are 30 per cent lower in people with symptomatic HIV infection compared with the HIV-negative or those newly infected.

Glutamine deficiency in the cells of the intestinal lining is one explanation for the chronic intestinal inflammation and malabsorption seen in many, if not the majority, of people with HIV. Whether this is a direct cause, or is due to the immune cells in the intestinal lining constantly having to fight off infections, is not clear. A recent study ⁽¹⁰²⁾ found that up to 70 per cent of people with HIV have problems absorbing xylose, a simple carbohydrate, and that nearly half had diarrhoea. The malabsorption is not solely due to failure to absorb nutrients: chronic inflammation may make the intestinal lining too permeable (so-called 'leaky gut syndrome'). This means both that molecules that are too large and potentially toxic get absorbed, and also that fluid leaks out of the blood and lymph vessels and into the gut, rather than the other way round, causing diarrhoea and essential nutrients to be excreted rather than absorbed.

Because of the theoretical link with glutamine deficiency, many PWHIVs use glutamine as a supplement to treat diarrhoea. There are many anecdotal reports of success. The only double-blind study conducted ⁽¹⁰³⁾ showed a trend toward improvement over a one-month period, but it did not reach statistical significance. The dose given here was 8g of glutamine a day, however, and PWAs with diarrhoea have tried very large doses of glutamine (up to 20g/day) in the first month till normal bowel movements are restored. In other areas of medicine, glutamine supplementation for patients who have had major abdominal surgery led to better intestinal function and shorter hospital stays ⁽¹⁰⁴⁾, though the glutamine was included in an intravenous feed until patients were well enough to eat normally.

In a 2001 study, more fully reported below under 'probiotics' ⁽¹⁶⁵⁾, glutamine was used as an add-on therapy in a group of 20 patients with nelfinavir-related diarrhoea if they did not respond to probiotics and soluble fibre supplements alone. All patients "appeared to get some benefit from the supplements", the authors report, and there was a significant decline in the use of loperamide to control diarrhoea.

Glutamine has also been used as a bodybuilding supplement, and it may have beneficial effects on people experiencing Aids wasting or lipoatrophy. It may improve the ability of the intestines to absorb nutrients, and reverse the loss of glutamine from the muscles during illness, which limits the body's ability to make new muscle cells.

One clinical trial ⁽¹⁰⁵⁾ involving 21 PWHIV/Aids showed significant improvements in weight and body cell mass (a measure of muscle tissue) in people taking the large amount of 40 grams of glutamine a day. Another ⁽¹⁰⁶⁾ showed similar improvements when glutamine was combined with the steroid oxandrolone, though the trial design made it impossible to decide whether the results were due to the glutamine or the oxandrolone.

Glutamine is also one of the three amino acids that are strung together to form the important antioxidant glutathione, which is deficient in PWHIVs. However there is little research on whether glutamine supplementation by itself improves glutathione levels. The supplement more often taken to boost glutathione is n-Acetyl cysteine (NAC): see under NAC for more information on glutathione. Dr Judy Shabert of Harvard University School of Medicine ⁽¹⁰⁷⁾ reports that glutamine supplementation in her patients does appear to improve glutathione levels, but controlled trials have yet to be done.

The amount of glutamine recommended is both difficult to take in capsule form and expensive. Most complementary nutritionists recommend it is taken as a soluble powder. Glutamine degrades quickly in solution, and is also quickly eliminated from the system, so it should be stirred into water and taken immediately before food three times a day. In the UK 200 grams of glutamine from manufacturers like Higher Nature will cost about £20 before any buyers' club discount.

There are few toxicities reported with glutamine. People with severe liver or kidney disease may have difficulty in processing the glutamine, and it should probably not be taken by PWHIVs with cirrhosis or steatosis caused by liver failure, whether due to hepatitis co-infection or drug side effects.

Carnitine is a naturally occurring substance essential to the human body. It was first isolated from muscle in 1905 and its function was demonstrated in 1952⁽¹⁰⁸⁾. For a while it was called vitamin B7 or vitamin BT. This name reflects both its importance and the fact that it does a similar job to many of the other B vitamins - being a link in the chain of biochemical events that liberates energy from food and metabolises fats.

Carnitine is a dipeptide; a molecule made out of two amino acids, methionine and lysine. It is required for energetic processes and it is found especially in muscle tissue. Because of this, the primary food source is meat, particularly beef and to a lesser extent pork. Smaller amounts are found in the whey portion of dairy products, wholemeal bread and some vegetables such as asparagus. ⁽¹⁰⁹⁾

The body also manufactures its own carnitine in the liver and kidneys - about 25% of the body's needs are met in this way. Vitamin C, vitamin B6, niacin and iron are required for its synthesis.

Carnitine occurs in many slightly different chemical forms. The ones used by the body are primarily l-carnitine, the 'left-handed' version (stereoisomer) of basic carnitine, and l-acetyl carnitine (LAC), where an acetyl group replaces a hydrogen atom.

The job of carnitines is to ferry long-chain fatty acids to and fro across the membranes of the mitochondria, the energy-producing components of cells, according to whether they are needed as 'fuel' for the body or to be stored. Medium-chain-fatty acids such as triglycerides (TGs) do not require carnitine to enter the mitochondria, but carnitine is needed to stimulate their energy production.

This is why carnitines are found particularly in the two body tissues that use the most energy, muscle cells (including heart cells) and the cells of the central nervous system. Without sufficient carnitine the fatty acids cannot be used and accumulate - either inside cells or in the circulation - a picture familiar to those who study lipodystrophy. Studies of HIV negative people have implicated carnitine deficiency both in heart defects, in chronic fatigue syndrome, and in dementia: several studies of giving carnitine supplements to elderly people, for instance ⁽¹¹⁰⁾, have shown improvements in mood, short-term memory, and cognitive function.

When it comes to the side effects of HV medication, nucleoside drugs like AZT drain carnitine from muscle cells, causing myopathy (muscle pain) and weakness ⁽¹⁰⁹⁾. AZT and other nucleosides - particularly the 'd' drugs ddI, d4T and ddC - also directly damage the mitochondria by inserting themselves into the mitochondrial DNA, and carnitine may be able to reverse the resultant loss of mitochondrial efficiency. ⁽¹¹³⁾ Nucleoside-related nerve damage also causes side effects like peripheral neuropathy (see below). Another organ vulnerable to damage is the kidney, where the nucleotide analogue adefovir, and to a lesser extent some of the other antiretrovirals, cause damage to the microtubules that filter urine ⁽¹¹⁰⁾.

It has been recently suggested ⁽¹¹⁴⁾ that LAC is the more biologically active form of carnitine, and that nucleoside drugs such as AZT, ddI d4T and ddC block the conversion of LC to LAC. Although damage to mitochondrial DNA is still implicated at the most important factor in nucleoside toxicity, this interference in LAC synthesis may exacerbate the process.

Early research into l-carnitine ^{(115, 116)} showed that in the test tube L-carnitine is able to suppress the production of tumour necrosis factor, elevated levels of which are thought to be responsible for wasting in HIV-positive people. Researchers also found that those who received L-carnitine reported less fatigue and greater energy

In 1994, Semino-Mora ⁽¹¹³⁾ showed that l-carnitine added to an in vitro culture could reverse damage to muscle cells cultured in a medium containing AZT. When cell cultures were exposed first to three weeks of AZT and then three weeks of concurrent LC, the absolute number both of muscle cells and their mitochondria increased, and the functioning of deficient mitochondria normalised.

In 1997, as mentioned above ⁽¹¹²⁾, Cifone and colleagues gave a short (five-day) treatment with six grams of intravenous LC per day to 10 patients with advanced AIDS .The treatment showed a 'strong and significant reduction' of peripheral blood mononuclear cell-associated ceramide, an intracellular apoptosis 'signal'. The proportion of CD4 and CD8 cells that were apoptopic decreased, with a resultant increase in cell half-lives.

In 1999, the same team of researcher ⁽¹¹¹⁾ gave three grams of oral LAC to 11 asymptomatic people with HIV. They found reductions in ceramide and an increase in ILGF-1, a growth factor able to protect cells from apoptosis, with resultant improvements in CD4 and CD8 counts.

Another team from the same University ⁽¹¹⁷⁾ - l'Aquila University in Italy - gave six grams of LC intravenously every day for four months to 11 patients coinfected with HIV and hepatitis C. These were patients who had chosen not to take antiretrovirals. On average, the patients' CD4 count increased by 100 cells and CD8 counts increased non-significantly, thus increasing the CD4:CD8 ratio.

(The fact that LC and LAC are non-toxic may indicate a useful role in treating HIV/HCV coinfected patients whose HCV infection means that they cannot tolerate anti-HIV drugs. Carnitine could be used as a maintenance therapy while HCV eradication is attempted.)

In 2001^(119,120), research teams in Montreal and Rome found that carnitine supplements may help to reduce triglyceride (TG) levels as well. The Canadian researchers enrolled 16 adult subjects, average age 43, all but one of whom were using protease inhibitors. Their average TG levels was about five times normal (5.67 mmol per litre where the average is 0.5-2.0). Their cholesterol was also about twice normal.

Subjects received three grams of L-carnitine orally daily for an average of nine months. Only one month after entering the study TG levels had decreased by an average of 39 per cent - a significant decrease from their pre-study levels. This decrease was maintained throughout the study. According to the researchers, "near-normal TG levels (3 mmol/Litre or lower)" were seen in 54 per cent of subjects after two months of L-carnitine use, and in 69 pre cent of subjects after their last lab test. However, there were no significant changes in cholesterol levels during the study.

In a pioneering and careful study cited above ⁽¹¹⁴⁾, Famularo and his team in Rome enrolled 12 HIV positive subjects who were using AZT with or without ddC, ddI or d4T, and who were starting to show symptoms of PN. No subject was using protease inhibitors. Their average CD4+ count was 84 cells. PN caused for reasons other than nucleoside analogues was ruled out by lab tests.

Researchers monitored 4 other groups of people, comparing them to the first group of 12:

11 PWHIVs without PN who used AZT alone

10 PWHIVs without PN who used ddI alone

13 HIV-negative people without PN

10 HIV-negative people who had PN for other reasons (e.g. diabetes-related).

When Famularo's team compared the levels of the different forms of carnitine in blood samples, they found little difference between the five groups. However, when they measured the level of LAC, the researchers found that the 12 subjects with PN taking nucleosides had, on average, the lowest level among the five groups studied. The differences in LAC levels were statistically significant.

The researchers suggested that the nucleoside analogue drugs were preventing the cells of the 12 subjects who developed PN from converting carnitine into LAC. This is the first time it had been suggested the LAC was the active form of the molecule.

Spurred on by this research, two studies in clinical settings looked at using LAC supplements to relieve peripheral neuropathy.

In one ^(121), presented at the First International Workshop on Clinical Pharmacology of HIV therapy, Dr Mike Youle of the Royal Free Hospital, London, reported on four patients with grade 2-4 drug-related peripheral neuropathy who received six months of L-acetyl carnitine therapy (1500mg twice daily). Skin biopsies were taken before commencing LAC therapy, and after six months of treatment, to assess re-growth of nerve tissue. Significant improvements in growth of small sensory fibres and nerve fibres in sweat glands were reported (p<0.001). All four patients reported a reduction in pain, numbness and tingling. Dr. Youle concluded that "Oral L-acetyl carnitine improves the symptoms of [peripheral neuropathy], even when nucleoside analogue antiretroviral therapy is continued."

Youle is conducting an ongoing study of 60 patients on the same regimen. Another 80 patients have been recruited in the UK and in the Netherlands to participate in a randomised study of intravenous LAC. The first group will receive LAC 500mg twice daily by intramuscular injections. The second group will receive a placebo twice daily.

In the EU, the Italian firm Sigma-tau manufactures a tablet form of LAC called "Nicetile". Recommended dosage is around 1500mg twice daily without food, as in the Royal Free study.

Even if you can get proper LAC from a health food shop, this will not come cheap. The least expensive LAC stocked by the large Nutri Centre shop in London W1, for instance, would cost £168.00 for 30 days' supply (list price) if you took 3g a day.

Furthermore, the Royal Free researchers have (unpublished) evidence to suggest that LAC is not well-absorbed in tablet form and are moving to a dissolved sachet formulation to stir into water.

At present the hospitals conducting LAC trials in the UK include the Royal Free and St Mary's Hospitals in London and the North Manchester Hospital, though other doctors may be willing to prescribe it.

LAC appears non-toxic, though there have been some reports of diarrhoea and nausea, particularly if it is taken with food. As with many amino acids, it appears best absorbed on an empty stomach anyway.

Glutathione is probably the most important of the body's arsenal of anti-oxidant substances. Antioxidants reduce (chemically render harmless) the reactive 'free radical' molecules - most of them containing reactive species of oxygen - which are produced as by-products of metabolism. Without antioxidants, tissues would oxidise and degrade, in a biochemical equivalent of rust.

Glutathione is a tripeptide - a molecule made of three amino acids, glycine, glutamate and, most relevantly for the purposes of this article, cysteine - strung together. As with certain other antioxidants, the business end of glutathione is the sulphur-containing cysteine molecule. The sulphur atoms in the compound have an affinity for reactive oxygen, which they neutralise by forming sulphate.

Glutathione appears to be essential for life, and without it we age faster and develop disease faster. Glutathione is particularly important in reducing the damage due to agents such as alcohol and Paracetamol (acetaminophen) in the liver, and is an essential part of the process that allows the antioxidant vitamins C and E to reconstitute themselves afresh once they have neutralised reactive oxygen species.

Tissues particularly vulnerable to low glutathione levels include rapidly-dividing and rapidly-replaced epithelial cells such as those that line the gut, blood vessels, lungs and joints, the myelin sheaths that insulate the nerves, and both red and white blood cells.

In addition, genetic damage from internal and environmental stresses is also dependent on cysteine and glutathione for successful repair. The transport of simple protein hormones, such as insulin, sex hormones, and adrenal hormones are dependent on glutathione to enable them to cross from the blood stream into the cell where the actual work gets done.

Glutathione also seems to act as an antagonist to inflammatory cytokines such as Tumour Necrosis Factor (TNF) and Interleukin-6 (IL-6). The job of these cytokines is to dampen down runaway immune reactions and tumour growth by encouraging cell self-destruction (apoptosis). But in chronic viral infections like HIV, these cytokines can themselves be overproduced, leading to cell death, immune decline and wasting.

There were more than 3,000 papers published on glutathione in the years 1997-2000 alone ⁽¹²²⁾, and a quick trawl of 33 HIV-relevant papers by John S James of Aids Treatment News ⁽¹²³⁾ suggests in how many diseases a disturbance of glutathione levels is a factor. James found papers suggesting that low glutathione levels, sometimes caused by factors like alcohol abuse, sometimes by disease, and sometimes by traumatic surgery such as organ transplants, have been found in patients suffering from the following conditions and/or have responded favourably to glutathione supplementation:

• Chronic bronchitis and the breakdown of lung tissue seen in emphysema and in lung transplants:
• Type II (non-insulin-dependent) diabetes - raising glutathione levels improved glucose uptake:
• The damage to blood vessels caused by diabetes, which can cause thromboses and damage to the retina:
• Certain kinds of epilepsy:
• Colon cancer, benign colon polyps and Crohn's disease:
• Kidney damage caused by hepatorenal syndrome:
• Coronary heart disease - patients with narrowing of the coronary arteries had lower levels of glutathione, 'good' high-density cholesterol and vitamins C and E:
• Anaemia, particularly among people with HIV:
• Kaposi's sarcoma.

The key factor in all these conditions is that they involve inflammatory processes, which the lack of glutathione is failing to damp down.

Although it is possible to buy glutathione itself in health food shops, taking it is probably a waste of (quite large amounts of) money, and may even be harmful. Glutathione does its work inside cells, and glutathione taken orally or even injected is flushed from the system too quickly to do any good. It is not just that glutathione is a fairly large molecule to get through cell membranes, but also that the body sees high plasma (as opposed to intracellular) levels of glutathione as a sign of disease, and corrects them. It does this by maintaining a balance between the glutamate and cysteine components of glutathione. High glutamate levels in the blood mean low cysteine levels in the cells, and vice versa. Thus taking glutathione itself can have a counter-productive effect, accelerating the loss of cysteine from the body which already appears to be caused by HIV infection.

Cysteine itself, and its close relative methionine, have been taken as supplements, but can be toxic and irritate the bowel.

However, the least toxic precursor of glutathione is n-acetyl cysteine (NAC). This is somewhat less expensive than glutathione and despite initial doubts has proved both to be bioavailable and to produce rises in glutathione levels inside cells. Another compound that has been tried is OTC or procysteine, but this is rarely available on over-the-counter settings. The trials below deal with NAC supplementation.

The mention of HIV anaemia and Kaposi's sarcoma above leads to the suggested role of low glutathione levels in HIV illness. This was suggested as a factor in progression to AIDS almost as soon as HIV was discovered. It is still seen as necessary to the process among many 'dissident' theorists, i.e. those that dispute the role of HIV. But orthodox scientists such as the co-discoverer of HIV, Luc Montagnier, have suggested that 'oxidative stress' is part of the reason why a virus with a comparatively low reproductive rate like HIV can cause so much damage.

But increased free radical production has been found in many other serious diseases, including cancer, hepatitis, and other viral diseases. And limited scientific evidence links lower levels of antioxidants (in particular vitamins C and E) to higher incidence of heart disease and cancer. So are increased free radicals, and lowered glutathione, a contributing cause of Aids and other serious diseases? Or are they just a passive marker indicating a body under stress? And will artificially correcting glutathione levels help?

Project Inform ⁽¹²⁴⁾ have commented: "The paucity of clinical trials is in stark contrast to the numbers of PWAs who take NAC and the sweeping recommendations drawn from in vitro studies." Nonetheless, as the 1990s progressed, the answer to the above questions became somewhat clearer.

While raising glutathione levels does not appear to be enough in itself to halt progression to Aids, HIV has some very particular properties which lead to a chronic and serious depletion of glutathione and cysteine that does not appear to be matched by other conditions. One of these properties ⁽¹²⁵⁾ is that HIV replication increases the level of 'unfriendly' cytokines such as tumour necrosis factor (TNF). TNF is known to activate and increase HIV replication. It does this by stimulating the nuclear transcription factor kB (NF-kB) in HIV-infected cells so that virus transcription and replication is greatly increased.

Glutathione interferes in NF-kB synthesis - as do many other substances, including aspirin (the subject of another 'supplementary therapy' enthusiasm).

Another aspect of HIV infection is that CD4 and CD8 cells appear to be divided into two populations in the body, containing respectively high and low levels of glutathione. HIV appears to selectively deplete the CD4 and CD8 cells that contain the highest amount of glutathione ⁽¹²⁶⁾.

One further twist to the tale is that, as mentioned above, people infected with HIV seem to have raised plasma glutamate levels. The German scientist who pioneered the study of glutathione and NAC in HIV, Wulf Dröge, ⁽¹²⁷⁾ found that even minimal elevations of plasma glutamate could cause a substantial decrease in cysteine levels inside the cells. Lowered cysteine levels in CD4 cells appear directly to reduce the cells' 'reactivity' towards pathogens, and also the amount of the immune-stimulating cytokine interleukin-2 (IL-2) they secrete. And, in a chicken-and-egg scenario, they also secreted more TNF, thus increasing HIV replication, thus driving forward the continued cycle of cysteine depletion.

While NAC supplementation does not improve viral load or CD4 or CD8 counts, a couple of studies detailed below have documented increased survival in patients given NAC (though others have not), and improved function of other parts of the immune system.

In 1992, de Quay et al. ⁽¹²⁸⁾ reported that a single oral dose of NAC could temporarily increase levels of cysteine and glutathione in some patients with HIV disease. De Quay observed a decrease in both glutathione and cysteine in HIV-infected subjects. Glutathione depletion was more marked in people who had progressed to Aids. The observation of cysteine depletion led him to the conclusion that glutathione deficiency is the result of cysteine deficiency and not of increased consumption of glutathione by oxidative stress. It is HIV that depletes the glutathione,: the lowered glutathione is not just a passive marker of continued infection.

Nine male patients at various stages of HIV infection were studied. Six uninfected volunteers served as controls. A single dose of NAC was given at the rate of 30mg/kg body weight - about two grams. Three- to four-fold increases in both plasma and CD4/CD8 levels of cysteine were seen in all subjects, yet intracellular glutathione increased moderately only in subjects at the least severe stages of HIV infection. The authors noted that synthesising glutathione out of its components inside the cell is a slow process, and that "a longer exposure to normal concentrations of cysteine may be required for a biologically meaningful increase in intracellular glutathione." One of de Quay's patients went on to take 600mg of NAC three times daily regularly. This resulted in a two-fold increase of the concentration of glutathione in CD4 and CD8 cells. However, De Quay was unable to determine "whether a sustained increase in intracellular cysteine affects the function of PBMCs [CD4/CD8 cells] or viral replication of HIV in the long term."

De Quay concluded: "Our results indicate that large doses of NAC should be administered repeatedly to achieve a sustained increase in intracellular glutathione." He added: "Further studies should determine whether pharmacological modulation of the glutathione status alters the natural history of HIV infection." He suggested that a tolerable daily dose for prolonged administration would be approximately 2 grams.

A total of 204 HIV positive volunteers were screened for the study, though the authors concentrated most of their analysis on the 97 who had CD4 counts under 200. Only 37 of these entered the full randomised study and ended up being given NAC or placebo. Many of the others were excluded because their glutathione levels were not low enough, since the purpose of the study was to research the effects of, and if possible correct, low glutathione levels. However some did have low glutathione but did not receive NAC for other reasons.

The 60 HIV positive people who did not enter the full NAC-supplementation study only had their glutathione levels measured at the start of the study - so there was no way to find out if levels declined over the study period. This was a major weakness, as not giving NAC to patients who started with normal glutathione levels and comparing them with a control meant nothing could be said about NAC as a preventative rather than remedial therapy.

However, when the 60 not given NAC were split into those who had high and low glutathione at the start of the study, there was a very strong association between low glutathione level and poor survival. People with CD4s under 200 and low glutathione had a three-year survival rate (remember this was pre-HAART) as low as 19 per cent - three to four times lower than people with CD4s under 200 but normal glutathione.

However, this did nothing to show whether the low glutathione level actually caused the poor survival.

Later analyses found the following:

• There was a strong correlation between low CD4 counts and low glutathione. A group of HIV negative controls had glutathione levels 28 per cent higher than those with HIV and CD4 counts above 200, and 41 per cent higher than those with CD4 counts under 200.
• Glutathione levels were more predictive of survival than CD4 counts.
• The only HIV drugs then available were the nucleoside analogues AZT, ddI or ddC. There was a significantly lower glutathione level in those taking these drugs, even though they were no more ill. This points tentatively towards low glutathione being a side effect of nucleoside drugs as well as HIV, and may indicate a continued use for NAC in the HAART era.

What of the 37 who started with low glutathione and were given NAC or placebo? They started with the extremely high dose of eight grams of NAC (or placebo) a day, but had the option of reducing this. Most did, bringing the eventual average dose down to 4.4 grams a day. Side effects such as nausea, digestive upset and rash were reported.

This level is still considered too high by researchers like Dröge, as it tends to upset the glutamate/cysteine ratio in a similar way to dosing with glutathione itself. Dröge and his team consider that doses over two grams a day are probably counterproductive and would result eventually in lower intracellular cysteine levels - the opposite of what is desired.

The randomised part of the trial only lasted eight weeks - after this everyone who wanted it was given open-label NAC. Results were then compared with patients who started with similar glutathione levels but who had never been given NAC.

The drop-out rate meant that only 25 patients were eventually given NAC.

These 25 did have a statistically better survival rate than patients with low glutathione who were not given NAC. In particular the NAC supplementation seemed to put off further progression during the first year of the trial. No patients given NAC died in the first year compared with four not given NAC.

In addition, the lower the baseline glutathione level, the higher the eventual rise: NAC supplementation, in short, seemed to normalise glutathione levels rather than push it to abnormally high levels.

A follow-up analysis in 1997, three years after the study ended, found a continued survival benefit in those who started with low glutathione and were given NAC. They had less than half the mortality rate of those who started with low glutathione but never given NAC. This was highly statistically significant. However, since there was no monitoring between 1994 and 1997, it's possible some other variable might have led to the higher survival rate.

Nonetheless, the Herzenbergs recommended NAC supplementation.

Leonore Herzenberg said: "The level of glutathione is generally tightly regulated in cells. If nature has gone to the trouble of maintaining those levels, logic says it should be restored to that level if you can. It's like a vitamin deficiency."

A Swedish group ⁽¹³⁰⁾ published the results of a randomised, placebo-controlled trial of NAC in HIV infection in August 1996. 45 volunteers with CD4 counts above 200 were assigned to receive either 800 mg of NAC per day or placebo for a period of 16 weeks. Also included was a comparison group of 16 HIV-negative volunteers. The HIV negative group had higher cysteine but not significantly higher glutathione concentrations than the HIV positive trial participants.

In contradiction to the Stanford study, glutathione levels remained unchanged, as did the investigators' measure of oxidative stress.

However, plasma cysteine levels did return to normal in the NAC group while remaining low in the placebo group. TNF levels also declined in the NAC group. Otherwise there was no appreciable benefit: CD4 counts declined slightly in the placebo group while remaining stable in the NAC group, but this difference was not statistically significant.

However, there were significant differences with the Stanford study. The groups studied were mutually exclusive: patients with CD4 counts below 200 in one, above 200 in the other. The Swedish cohort may well have had a higher average glutathione level to start with, so that any significant remedial effect of the NAC would have been harder to detect or taken longer than 16 weeks to become evident. And the dose of NAC was much smaller. The most one can say is that it may give an indication as to what is the lowest useful dose of NAC.

So far these studies had only shown that glutathione levels could be restored with NAC supplementation and that this appeared to confer a small survival benefit. But they were so underpowered, and the effects of HAART, which came in immediately afterwards, so much more powerful, that the NAC/glutathione saga might have been laid to rest. However, two studies reported in 2000 seemed to lend more credence to the idea that low glutathione and cysteine levels were a phenomenon of major importance throughout the course of HIV infection, and that antiretroviral therapy in itself did little to restore them.

The first suggestive study ⁽¹³¹⁾ was an animal study that showed that the Tat protein of HIV might be the 'villain' in the case of the missing glutathione. Mice which were genetically modified to produce HIV-1 Tat had very low glutathione levels. This suggested that the low glutathione levels found in persons with HIV could be a specific effect of this particular virus -- not only a consequence of any viral infection, or the immune stimulation caused by HIV, or digestive malabsorption.

The next news, in February 2000, created much more of a stir. Wulf Dröge and his team presented three studies ⁽¹³²⁾ which all appeared to show that, at all stages of HIV infection, and regardless of whether patients were on medication, people with HIV lost large amounts of the element sulphur from their bodies.

Droge measured plasma sulphate levels in 64 asymptomatic PWHIVs and 65 people without HIV. They found that the PWHIVs had about one-third higher plasma sulphate concentrations. (Remember that the end result of glutathione's anti-oxidant activity is the conversion of reactive oxygen radicals to sulphate ions.)

The last study, comparing 19 HIV positive volunteers with 21 HIV negative ones, found far higher sulphur concentrations in urine too. This seemed to indicate that the people with HIV were losing frightening amounts of sulphur from their bodies every day. The sulphur in the urine was largely in the form of cysteine.

Uninfected people excrete three grams or so of cysteine in their urine every day. The HIV positive volunteers appeared to be excreting the astounding amount of 10 grams a day - a net daily deficit of seven grams, or 2·5 kilograms a year.

It is important to note that although Dröge speculated that all this sulphur was coming from the breakdown of glutathione, there was no direct evidence of this. Steve de Rosa, a scientist who worked on the Stanford study, was cautious in drawing conclusions. "Glutathione and sulphur are telling us that HAART is merely the first step [in HIV treatment]," he said. Other scientists puzzled that even patients taking indinavir - a drug that contains sulphur -showed the same losses.

Members of Droge's team from the University of Heidelberg then went ahead with two seven-month studies of NAC supplementation ⁽¹³³⁾. One compared NAC with placebo in 37 subjects taking antiretrovirals (average viral load: about 8,500). The other compared NAC versus placebo in 29 subjects not taking antiretrovirals (average viral load: about 37,500). Both groups had CD4 counts between 200 and 500.

The dose of NAC given started at anything between 600 mg to 3.6 grams and was then adjusted according to whether high glutamate concentrations were building up or not. The average daily dose ended up being about 1500 mg - in fact dosed as three grams every other day.

Average CD4 and CD8 counts and average HIV viral load did not change during the study in any group. However, the numbers and effectiveness of another component of the immune system, the Natural Killer Cells, improved. TNF levels went down in the group not on antiretrovirals. And levels of albumin - a measure of how well the body's need for protein is being met - went up.

In addition, this level of supplementation did appear to correct the net loss of cysteine. The team also discovered that NAC absorption was increased when it was taken with acidic fluids such as fruit juice.

Other studies continue to show suggestive links between glutathione/cysteine levels and all kinds of aspects of immune and cellular function. For instance, in 1999, Farook Jahoor and colleagues ⁽¹³⁴⁾ compared GSH levels in red blood cells from five HIV-positive men to those in five HIV-negative controls (three men and two women). Although the diet of both groups contained similar amounts of protein and antioxidants, the glutathione levels in both plasma and red blood cells from the HIV-positive men were considerably lower that those of the control group. After the HIV-positive group received one week of supplementation with NAC, both plasma and red blood cell levels were similar to those of the control group.

And another study ⁽¹³⁵⁾ suggests that low glutathione levels may be cause by other chronic viral infections as well as HIV, in particular hepatitis B and C. Researchers from Germany report that adding NAC (N-acetyl cysteine) to hepatitis B-producing hepatocyte (liver cell) lines can reduce hepatitis viral load 50-fold. Glutathione is used by the liver to help break down toxins, so we are back in the chicken and egg situation: is the low glutathione directly caused by the hepatitis viruses, or is it just a passive marker of the cell damage caused by the viruses?

• We do not know if long-term use of NAC as a supplement slows progression to Aids, especially in patients who start with normal glutathione levels
• We do not know if it helps to reduce the side effects of antiretrovirals or delay drug failure
• It remains unproven generally that artificially boosting glutathione levels will improve the poor prognosis of people with low glutathione levels
• We do not know the ideal dose: drawing a line between the Stanford and the Swedish studies would point to one of about 1500-1800mg, spread through the day in two or three doses (NAC is quickly excreted)
• We do not know the exact reason that people with HIV infection (and, possibly other chronic viral infections) have low glutathione levels and exactly how this contributes to disease progression.

Until we do long-term longitudinal studies comparing the progress of people who take NAC with those who do not, answers will not be forthcoming.

Nonetheless, the consensus among scientists who have studied it seems to be: why not take NAC? Staal et al, in a Lancet review of the subject ⁽¹³⁶⁾, says: "NAC has antiretroviral effects in vitro, low toxicity in vivo, a long history of use in patients, can be given orally in a palatable form and is inexpensive." And Leonore Herzenberg says: "We are not saying that people should take NAC, just that the data are consistent with NAC being useful [in prolonging survival]. NAC is non-toxic and fairly inexpensive, so why not take it?"

As noted above, side effects of NAC are limited to nausea and diarrhoea and, in rare cases, rash, and are very dose-dependent.

Some antibiotics, including amphotericin, ampicillin, erythromycin, and tetracycline, may be inactivated or their effect lessened when used with NAC.

Paracetamol (Tylenol/acetaminophen) and similar drugs are known to reduce levels of glutathione; given that alternatives are readily available, it might be prudent for people with HIV to avoid Paracetamol. NAC is available as an over the counter supplement in health stores. It also has specialised medical uses: it is available in a prescription-only solution as Mucomyst® (Bristol-Myers Squibb), Mucosil® or , outside North America, Fluimucil® that can be ingested or aerosolized and inhaled to loosen sticky mucus in lungs.

At a dose of 1500mg/day, 30 days' supply of NAC at UK retail prices before any discounts would cost £21-£26 (2001 prices).

NADH is a chemical relative of niacin (vitamin B3, nicotinamide). It is one of the chemicals produced in the cycle of chemical reactions that enable the body to produce ATP - adenosine triphosphate - the body's basic fuel, a substance which is the body's most fundamental source of chemical energy. In this it plays a part in the same metabolic pathway as some other chemicals looked at in this section such as vitamin B1, folic acid, coenzyme Q10 and l-acetyl carnitine.

Its ATP-releasing function suggested a use in patients with chronic fatigue. One double-blind, placebo-controlled study⁽¹⁷⁷⁾ gave 10mg of NADH or placebo once a day to 28 HIV negative patients with chronic fatigue. Patients received either NADH or placebo for four weeks: then there was a wash-out period of three weeks; then for the last three weeks those who had got placebo previously received NADH and vice versa.

The result was a modest improvement in fatigue symptoms in eight of the 26 patients. Not that impressive: this is however being followed by an open-label study which will look at other indicators.

These modest results have not prevented NADH being sold under names such as 'Alert'. In the UK NADH retails at the relatively expensive price of £16.95 for 30 5mg tablets (i.e. £35 for a month's supply). 10mg should be taken every morning at least 30 minutes before breakfast.

"Probiotics" as a term conveys pretty well what is involved in this kind of supplementation - whereas antibiotics get rid of bacteria, probiotics add them⁽¹³⁷⁾. They are supplements of 'friendly' bacteria, used to top up the levels of useful bacteria that normally live in the gut.

There are more individual bacteria living in and on the human body - especially in the digestive tract - than there are cells in the body. The human gut alone normally contains about 1kg of living bacteria, and dead ones, along with shed intestinal cells, actually make up most of the bulk of faeces. Most of these bacteria, far from causing disease, are vital to good digestion and may be important for the proper functioning of the immune system - indeed, they may actually act as part of it, secreting substances which neutralise carcinogens (cancer-causing chemicals).

Fermentation of food by bacteria is the important last stage in digestion. Without bacterial fermentation, food is not digested or absorbed properly. 'Friendly' bacteria compete with pathogenic bacteria and other organisms like E. coli or Candida that cause food poisoning, diarrhoea and gut inflammation. And, particularly in children, there is growing evidence that the these bacteria have systemic as well as local effects: they appear to play a part in stimulating the immune system and helping it develop. Lack of them causes immune defects not only in the gut but throughout the body.

The best known probiotics are the lactic acid-producing lactobacilli and bifidobacteria, which are widely used in live yoghurts and other dairy products, and are also available in capsule form. Other organisms like the yeast Saccharomyces boulardii have also been used as probiotics.

Prebiotics are particular kinds of carbohydrate (the oligosaccharides and others) which the useful bacteria preferentially feed on. Taking them is intended to stimulate the growth of organisms already there rather than replace or supplement ones which are lacking.

Probiotics and to a lesser extent prebiotics are a very popular form of supplementation, forming the basis of a whole industry of live-culture based products like Yakult, Proviva and the various live yoghurts. Taking them has been credited with near-miraculous abilities to improve health, particularly among those alternative health specialists that see fungal infections like candida at the root of much ill-health and immunosuppression. But many claims for the potential health benefits of supplementing with both probiotics and prebiotics in fact remain unproven.

Overdosing on intestinal bacteria, however benign, can cause digestive complaints in itself, and very occasionally endemic lactobacillus and bifidus have caused more serious illness in immunocompromised individuals^(138,139). More often, however, these supplements are too weak rather than too strong: because they are composed of living organisms, the problem is keeping them alive. Many probiotics contain far fewer viable bacteria than claimed, they degrade quickly if not stored under the right conditions before sale (e.g. refrigeration at the correct temperature), and often not enough bacteria survive the passage through the acidic environment of the stomach to reach the intestines. Another practical difficulty, as we see below, is that research is revealing that different strains even of the same species vary widely in their effectiveness. As with the similarly multifarious family of bioflavonoid chemicals (see above), research over time will hopefully clarify exactly which strains of bacteria are effective and which are useless.

Probiotics taken as supplements do not permanently colonise the host, and need to be taken on a regular basis.

As the British Medical Journal says⁽¹³⁷⁾, most scientific studies of probiotics have been "observational rather than mechanistic, and thus the processes responsible for many probiotic phenomena are seldom explained". However there have been enough studies done to show at suggest that probiotic supplementation can be beneficial in several different ways.

Preventing gut infections

There is a relatively large volume of literature that supports the use of probiotics to prevent or treat intestinal disorders. However, the scientific basis of probiotic use has been firmly established only recently, and sound clinical studies have begun to be published.

The adherence of probiotics to the gut epithelium is not a universal property of lactobacilli or bifidobacteria and is not essential for successful probiosis, at least in terms of helping with gut infections. Feeding Bifidobacterium breve to children with enteritis eradicated Campylobacter jejuni from their stools, although less rapidly than in patients treated with erythromycin.⁽¹⁴³⁾

Supplementation can even help with viral infections: supplementation of infant formula milk with B bifidum and Streptococcus thermophilus reduced episodes of diarrhoea in children in hospital caused by rotavirus, and reduced their infectiousness.⁽¹⁴⁴⁾

Lactobacilli have been widely used in treating diarrhoeal diseases in adults such as pseudomembranous colitis, but the results have been mixed. The GG strain of Lactobacillus successfully eradicated Clostridium difficile in five patients with relapsing colitis.⁽¹⁴⁵⁾ Approximately 10 billion Lactobacilli were fed daily in skimmed milk. Diarrhoea was immediately relieved in four patients; the other patient also improved after further antibiotic and probiotic treatment.

It appeared that the Lactobacilli did not simply crowd out pathogens: colitis has been shown to be exacerbated by a toxin secreted by Clostridium bacteria, and the Lactobacillus GG had been shown not only to colonise the gut but also to secrete an antimicrobial product that was active against C difficile, as well as a range of other micro-organisms. ⁽¹⁴⁶⁾

However, not all lactobacilli are effective in combating enteric pathogens. 23 healthy volunteers were given a commercial product containing L acidophilus and L bulgaricus and were then challenged with enterotoxigenic E. coli.⁽¹⁴⁷⁾ They did not differ in respect of attack rate, incubation period, and duration of illness from control subjects given a placebo.

The yeast Saccharomyces boulardii has also been used in studies on prevention and treatment of diarrhoea associated with C difficile infection. ⁽¹⁴⁸⁾ Of 180 patients in a double-blind controlled study, 9.5 per cent of those receiving Saccharomyces had diarrhoea compared with 22 per cent of patients given a placebo. Prophylactic use of Saccharomyces reduced the incidence of diarrhoea associated with C difficile infection, although it did not prevent infection.

Of particular interest to PWHIVs who travel may be experiments using probiotics to reduce the incidence of 'travellers' diarrhoea' caused by unfamiliar strains of organisms like E. coli. In one trial ⁽¹⁴⁹⁾ the incidence of diarrhoea was reduced from 71 per cent to 43 per cent in tourists going to Egypt who were given capsules containing S thermophilus, L bulgaricus, L acidophilus, and B bifidum.

Probiotics and prebiotics seem to protect against cancer of the digestive system in several ways. Probiotics have been found to inhibit intestinal bacterial enzymes involved in the synthesis of colonic carcinogens. Lactobacilli are able to 'soak up' the carcinogenic chemicals produced when fats are cooked at high temperatures. It has been shown even killed bacteria can do this; the carcinogens attach chemically to the constituent lipid molecules of bacterial cell walls. ⁽¹⁵⁰⁾ Lactobacilli are able to degrade the highly carcinogenic chemicals called nitrosamines. ⁽¹⁵¹⁾

Purified bifidobacterial cell walls also have anti-tumour activities: the cell wall of B infantis induces activation of the immune cells called phagocytes which destroy growing tumour cells. ⁽¹⁵²⁾

This phagocyte-stimulating activity is an example of the fact that intestinal bacteria have immune stimulating effects, which are not just mucosal (acting locally on the gut lining), but systemic. Bacteria in the colon secrete substances that stimulate the epithelial cells lining the intestine (themselves part of the immune system), and B and T lymphocytes in the blood. ⁽¹⁵³⁾ Bacteria such as the Bifidobacteria produce immune-stimulating substances that bind to epithelial cell walls, often carrying antigens (immune-stimulant substances) with them. These substances include lipopolysaccharides, peptidoglycans, and lipoteichoic acids ⁽¹⁵⁴⁾.

Yoghurt lactobacilli act on the cellular arm of the immune system - they bind in vitro to CD4 and CD8 cells and also stimulate the large white cells called macrophages, while some bifidobacteria seem to stimulate more the other (humoural) arm - they induce formation of large amounts of the antibody protein IgA.⁽¹⁵⁵⁾ However, this ability is restricted to very select strains: out of 120 strains of three species of Bifidobacteria tested, only three B breve strains and one B longum strain induced appreciable synthesis of IgA.

L acidophilus and B bifidum, given in capsule form to elderly people ⁽¹⁵⁶⁾ , produced appreciable changes in inflammatory and immunological responses. The probiotics reduced inflammation of the colon considerably, but did not affect the numbers of gut B and T lymphocytes. However, subjects experienced a greater increase in B cells in peripheral blood than did controls. At the other end of the age range, Lactobacillus GG has been used to regulate the immune response in 31 babies aged 2-16 months suffering from cow's milk allergy and eczema.⁽¹⁵⁷⁾ It resulted in a considerable improvement in their condition.

The use of probiotics to 'prime' infants' immune systems continues to be studied and show good results. This may be particularly important in a modern environment where hygiene measures have produced 'under-stimulation' of infant immune systems and where the gut bacteria of babies have, for the first time in history, tended in the last two decades to come more from the hospital environment than from the babies' mothers. ⁽¹⁵⁸⁾

For instance in 1999 a double-blind randomised study of 571 infants in 18 day-care centres in Finland ⁽¹⁵⁹⁾ gave half the group milk fortified with the GG strain of Lactobacillus for seven months. Children in the Lactobacillus group had 16 per cent fewer days of absence from day care because of illness. There was also a relative reduction of 17% in the number of children suffering from respiratory infections with complications and lower respiratory tract infections - illustrating that the probiotic supplementation was having systemic effects.

A similar study in Peru⁽¹⁶⁰⁾, giving children Lactobacillus GG as a gelatine capsule at home six days of the week for 15 months, found 13 per cent less diarrhoea in the Lactobacillus group and 20 per cent less in children not breast-fed. And a Japanese study⁽¹⁶¹⁾ by the manufacturers of the popular probiotic drink Yakult, using Bifidobacterium breve, found a significant reduction of the frequency of rotavirus shedding in stool samples form a group of children in a children's home during the administration of the bacteria.

The intestinal improvement and immune stimulation observed in people with incomplete or depleted immune systems, namely infants and the elderly, suggest backing for the use of probiotics in people with lowered immunity due to HIV infection. Unfortunately, few studies have been done.

A study in immune-depleted mice ⁽¹⁶²⁾ found that probiotic supplementation appeared to reduce the number of infections in mice challenged with Cryptosporidium, which causes intractable diarrhoea in some PWAs. However, human studies have failed to show the same benefit. One of the few studies of probiotics in HIV-positive people⁽¹⁶³⁾ did not show increases in friendly bacteria after three weeks of use.

Probiotic supplements may be able to help with protease-inhibitor-related diarrhoea. In a 2001 study, ⁽¹⁶⁵⁾ 20 patients taking nelfinavir who had diarrhoea participated in a 12-week prospective study. 16 patients were given 1.2 grams a day of L. acidophilus and bifidus, along with 11 grams a day of a soluble fibre preparation, which helps absorb water from the stools and bulk them up. The other four patients acted as a control group. Diarrhoea completely resolved in nine out of the 16 patients. If after four weeks patients did not obtain full relief with probiotics and soluble fibre alone, 10 grams a day of l-glutamine were added. These remaining patients also "appeared to get some benefit", according to the authors, with a significant decline in stool frequency and less usage of the anti-diarrhoea medication loperamide (Imodium).

These are substances intended to stimulate the growth of the 'right' intestinal bacteria by providing the kind of nutrients they prefer. To be effective, prebiotics should escape digestion in the upper gut, reach the large bowel, and be utilised selectively by a restricted group of micro-organisms that have clearly identified, health promoting properties. The food ingredients most likely to meet these criteria at present are the oligosaccharides, carbohydrates made of several individual linked sugar units (monosaccharides). These include inulins and their derivatives, the fructo-oligosaccharides. These carbohydrates occur naturally in Jerusalem artichokes, onions, chicory, garlic, leeks, and, to a lesser extent, in cereals. Other oligosaccharides such as raffinose and stachyose are the major carbohydrates in beans and peas. These simple molecules can also be produced industrially, and a number of new potential prebiotics are being developed for this market. The degree of polymerisation of these substances refers to the number of individual monosaccharides in the molecule.

Not all non-digestible oligosaccharides have prebiotic properties, and inulin, fructo-oligosaccharides, and (to a lesser degree) galacto-oligosaccharides dominate the published reports.

Their use in people with HIV may cause either benefits or problems. Fructo-oligosaccharides pass undigested through the small intestine, and are broken down only when bacteria get to work on them in a process of fermentation - producing, as in all fermentation, carbon dioxide gas as a by-product. Because of this they can exacerbate rather than relieve diarrhoea, and bloating and flatulence are often a complaint, particularly when large doses are taken. (It is these chemicals that cause the notoriously 'windy' effects of vegetables like beans, artichokes and onions.) They are, however, completely non-toxic.

In controlled dietary studies with human volunteers, fructo-oligosaccharides (15 g/day) increased faecal bifidobacterial numbers 10-fold while reducing clostridia and enterobacteria counts, showing that species composition of the microbiota could be selectively manipulated through diet. Feeding fructo-oligosaccharides (8 g/day) to elderly people increased faecal bifidobacteria 10-fold, ⁽¹⁶⁶⁾ while ingestion of soybean oligosaccharides (10 g/day) resulted in a smaller, though still appreciable increase in bifidobacteria. ⁽¹⁶⁷⁾ At present, no clinical studies on the use of prebiotics to prevent diarrhoea have been reported.

When a chewable tablet preparation of fructo-oligosaccharides called Neosugar (4 g/day) was given to healthy volunteers,⁽¹⁶⁸⁾ it increased the intestinal bifidobacteria and reduced appreciably the activities of enzymes which produce carcinogenic and gene-toxic chemicals such as glucuronidase and glycocholic acid hydroxylase, indicating the potential of prebiotics to reduce or prevent cancer.

Probiotic supplements come in a vast number of different formulations prepared to very different standards. Remember this is a supplement containing living organisms, so storage conditions are crucial: a supplement that has been on an unrefrigerated shelf for months may contain not one viable bacterium. This is one area where it pays to take advice, shop around and pay a bit more for better quality. Compare the number of viable organisms claimed on the label (this is more important than capsule weight), buy supplements that have been refrigerated, do not buy more than one month's supply at a time, and keep them in your own fridge. The majority of supplements in the UK cost from £12 to about £25 for a one-month supply, though there are also loose powder formulations that cost more.

For example: the most popular prebiotic sold by London's Nutri Centre, 'Bio-acidophilus', is claimed to contain three billion viable organisms of Lactobacillus acidophilus and Bifidobacterium bifidum when sold, and retails at £17.45 for 60 capsules.

Supplements are formulated with different additional buffers and nutrients. Many contain milk powder or lactose - if you are lactose-intolerant check whether they contain these. Others such as Bio-acidophilus contain fructo-oligosaccharide prebiotics (see above) which cause diarrhoea and/or flatulence in some people. You may find that probiotic supplements make diarrhoea worse until you find one that is right for you.

It is best to take probiotics with meals as this seems to ensure passage into the large intestine.

These particular supplements are often referred to simply as sterols and sterolins. These, however, are misleading terms. Sterols and sterolins are a vast range of different fat molecules that are found in both plants and animals - cholesterol is one of them. This and many of its chemical cousins form the building blocks of steroid hormones, cytokines and many other important body chemicals as well as supplying the material for cell membranes and other body components.

The sterols and sterolins for which specifically anti-HIV and immune-boosting properties have been claimed are among the sterols found only in plants (phytosterols). The chemically active sterols appear to be beta-sitosterol or BSS (see formula below) and beta-sitosterolin, the glycoside of the sterol, often abbreviated to BSSG. These form about 55 per cent of purified phytosterol preparations. The closely similar chemicals campesterol and stigmasterol form most of the other 45 per cent and perform similar roles.. These are dense, soapy fats which are often difficult to absorb when the raw plants are eaten as they are closely bound to plant fibres.

Sterols as possible anti-HIV agents have been championed by one investigator in particular, Professor Patrick Bouic of Tygerberg University in Cape Town, who has conducted numerous trials of these substances. He has suggested ⁽¹⁶⁹⁾ that they could form the basis of "a non-drug AIDS treatment strategy that is highly effective," particularly in resource-poor countries. Other complementary product suppliers are not so enthusiastic: DAAIR in New York comment that "Studies in HIV suggest at best some slowing of CD4 loss". ⁽¹⁷⁰⁾ The use of sitosterols as immune boosters in combination with HAART has not been subject to study.

Prof. Bouic's investigations into phytosterols were originally suggested by his investigations into the South African sweet potato (Hypoxis rooperi), a plant used in traditional Zulu medicine which is particularly rich in the chemicals.

His first reports on their effects date from in vitro experiments in December 1996⁽¹⁷¹⁾. He says he found that a BSS/BSSG mixture in a ratio of 100:1 induced cell cultures to increase production of the immune-stimulating cytokines interleukin-2 (IL-2) and gamma interferon by between 17 and 41 per cent. Another experiment showed an increase in Natural Killer Cell activity resulting in the destruction of experimental cancer cells with the sterol/sterolin mixture. The peak activity of the sterol/sterolin mixture occurred at six hours in the in vitro experiments.

An in vivo experiment on eight HIV-positive volunteers at the same time indicated a T-cell proliferative response that varied from 20 per cent to 920 per cent (this latter is an astonishing increase, raising a count of, say 50 to 460) after only four weeks on the sterol/sterolin mixture. These results, he claimed, were achievable on a plasma concentration of only one femtogram (one million-millionth or 10^-15 grams) per millilitre - representing about 150 molecules of BSS and 10 of BSSG.

In September 1997 ⁽¹⁶⁹⁾ Prof. Bouic published two pilot studies on cats infected with FIV, the feline equivalent to HIV. In both studies the cats receiving the BSS/BSSG mixture maintained stable CD4 lymphocyte counts and suffered no deaths due to FIV within three years.

These results prompted an open trial of 80 human patients with HIV over a three year period, with clinical monitoring every three months. The average CD4 lymphocyte counts remained stable over 27 months with no significant declines, similar to the results of the cat study. The mechanism of this action appeared to be an increase in the CD4 lymphocytes' half-lives. This may not have been due attributable to the BSS mixture stimulating the release of IL-2 so much as it suppressing the release of the antagonistic cytokine IL-6. A pro-inflammatory lymphokine, interleukin-6 has been implicated in the induction of HIV replication in infected cells. The study showed a significant decrease in interleukin-6 levels in the sterol/sterolin treated group , whose average viral load also decreased.

The sterols/sterolins had no anti-viral activity, but the immunomodulatory activity on interleukin-6 levels appeared to lead to lower viral load levels.

HIV infection is not the only condition treated with sitosterols by Bouic's team. He also conducted a double-blind study⁽¹⁷²⁾ of 43 persons infected with pulmonary tuberculosis who were receiving receiving conventional multi-antibiotic treatment, to see if the addition of a BSS/BSSG mixture could improve the clinical outcome. The study took place over six months. The group receiving the sterol/sterolin mixture showed a significant weight gain over the placebo group. As well, the treatment group showed a significant increase in lymphocytes and eosinophils. Other lab parameters remained the same between the two groups. The increase in lymphocytes is consistent with previous experiments indicating a T-cell proliferative effect. The increase in eosinophils, said Bouic, was difficult to explain, since this is an allergic reaction, and no previous allergic response had been attributable to the ingestion of the phytosterols. However, other data indicate there may be a relationship between the rise of CD4 lymphocytes and eosinophils.

Both Bouic's team and other investigators⁽¹⁷³⁾ have found that both BSS and BSSG induces rises in insulin in experiments in rats and protects them from the effects of glucose overload.

One very well-attested use for sitosterols is in the control of benign prostatic hypertrophy (BPH), the enlargement of the prostate gland common in older men, which may lead on to prostate cancer in a minority of cases. Two randomised placebo-controlled German studies^(174,175) gave doses of beta-sitosterol varying from 60 to 130 mg twice daily to half of a group of 350 men. Peak urinary flow improved in both studies, as well as an improvement in the subjective symptoms of BPH. The investigators suggest that the proven effectiveness of certain herbal remedies for BPH such as saw palmetto and pumpkin seeds may be due to their sitosterol content.

Positive results have also been observed in subjects with rheumatoid arthritis where the immune-regulating effects of BSS and BSSG have a positive effect on joint inflammation.

It is a pity that this particular supplement has only been investigated by one scientist and his team when it comes to its use for HIV infection, and that no studies have been done on patients taking HAART. One needs to be cautious in interpreting the results not least because the published papers do not specify dosing and dietary regimens, the relative state of health of subjects, and whether they were taking other mediations. Patrick Bouic is also involved in the firm that produce Moducare, the only proprietary brand of BSS and BSSG developed specifically to stimulate the immune response. However the results in patients not taking antiretrovirals would appear to be impressive enough to suggest a useful role for these compounds.

Timing and frequency of dosage and food restrictions would appear to be crucial for the successful use of Moducare. Phytosterols are absorbed by the digestive system at a rate 800 to 1,000 times less than cholesterol, and absorption is completely blocked if they are taken alongside animal or dairy fats.

Some authors recommend an optimum daily intake of 200-300 mg⁽¹⁷⁶⁾, whether from preparations like Moducare, phytosterol-containing herbs like saw palmetto and devil's claw, or foods that contain high levels of phytosterols like pumpkin seeds. (Moducare itself is prepared from soya beans). Moducare itself contains only 20 mg of BSS and 200mcg of BSSG per capsule. DAAIR in New York recommend starting with six capsules per day for the first three weeks and then scaling down to two or three a day.

The fact that BSS and BSSG appear to reach their peak effect within six hours also suggests a relatively frequent intake, though attempts to take it three times a day, well away from food, could result in the same kind of adherence difficulties familiar to patients taking unboosted indinavir.

No toxicities have been reported with BSS, BSSG or related phytosterols.

A 90-capsule bottle of Moducare - about a month's supply - currently costs £17.95 from London's Nutri Centre.