Many people with HIV take dietary supplements, vitamins or herbal remedies in the hope of boosting or protecting their immune systems and general health.
There is some evidence that taking multivitamins can help slow the rate of HIV disease progression in settings where HIV treatment is not available. However, vitamins and supplements are not a replacement for HIV treatment and are, at best, a useful support.
It's known that 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 1000mg per day can cause kidney stones, diarrhoea and the hardening of the arteries, and have been shown to reduce concentrations of the now rarely used 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.