Vitamin B6

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. Although deficiency is rare in people eating a normal Western diet, low levels have been observed in people with HIV. Deficiency is difficult to diagnose.

The vitamin can reduce the toxicities of the tuberculosis and Mycobacterium avium intracellulare (MAI) drug isoniazid, and one study amongst HIV-positive gay men suggested that those deficient in vitamin B₆ were more likely to be depressed and anxious and that when this deficiency was corrected, there was a significant decrease in depression.¹ It has been suggested that AZT (zidovudine, Retrovir) use increases the need for this vitamin, although studies have shown no clear link.

Another study treated 12 HIV positive people with 20 to 25 mg of vitamin B₆ and observed a small increase in CD4 cell count amongst 8 of the 12 over a six month period. In contrast, an untreated control group showed no improvement in CD4 count.²

High intake of vitamin B₆ (20mg per day or more) has been associated with a reduced risk of developing AIDS in a cohort followed for six years.³

Doses of more than 2g a day have been shown to cause nerve damage. Most nutritionists believe 50mg to be adequate for anyone. Good food sources of vitamin B₆ are meat, whole grains, brewer's yeast and whole grains, wholemeal bread.

Vitamin B₆ is also known as pyridoxine.