Vitamin D

There is limited and conflicting evidence about this vitamin. 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 which combat opportunistic infection such as tuberculosis.

More recent research has found evidence that 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. 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.

Vitamin D production is stimulated by sunlight, but the vitamin is not abundant in foods, except for oily fish, egg yolks and liver.

'Thinning bones' or osteoporosis is emerging as a common condition among people with HIV. Vitamin D supplementation, along with calcium and steroids, is being tested as treatment for HIV-infected people with osteoporosis or the milder condition of osteopenia.