Many people with HIV take dietary supplements, vitamins, or herbal remedies in the hope of boosting or protecting their immune systems and general health.

Evidence that these have any beneficial effect is somewhat thin. What’s more, certain supplements, such as large doses of garlic, can stop some anti-HIV drugs working properly. Most HIV specialists would advise that a healthy, balanced diet is enough to meet your nutritional needs. Megadoses of nutritional supplements are not recommended.

Large doses of vitamin A can cause liver and bone damage, as well as vomiting and headache.

Vitamin C doses above 1,000mg per day can cause kidney stones, diarrhoea and the hardening of the arteries, and have been shown to reduce concentrations of the protease inhibitor indinavir (Crixivan).

Zinc doses above 75mg per day have been associated with copper deficiency as well as a shortage of white and/or red blood cells.

Selenium doses of 750 micrograms or more per day have been associated with immune suppression.

Vitamin B6 doses above 2g per day can cause nerve damage, but doses as low as 50mg per day have been known to cause peripheral neuropathy (painful nerve damage), particularly in the feet.