Men who are infected with the virus that causes AIDS appear to progress to the full-blown disease much more quickly if they are deficient in vitamin B12, researchers said Friday.
Scientists from Johns Hopkins University said a study of 310 gay and bisexual men who were infected with HIV, the AIDS virus, found that those with adequate blood levels of B12 remained free of the disease for about eight years, compared with four years for those deficient in the nutrient.
The researchers, led by Dr. Alice M. Tang of the Johns Hopkins School of Hygiene and Public Health, said two other important nutrients tested, vitamin B6 and folic acid, had shown no similar link with the timing of the development of AIDS by men infected by HIV.
Tang said that even though her work and similar observational studies by other researchers did not prove that B12 deficiencies meant less favorable outcomes for HIV-infected patients, the link was strong enough to be examined more rigorously in controlled clinical trials.
Tang said results of her study, published in the February issue of The Journal of Nutrition, suggest that HIV-infected patients should have their B12 levels monitored and take steps to maintain adequate nutrition.
The B vitamins, including B12 and folic acid, play crucial roles in protein and DNA synthesis, experts say, and deficiencies can lead to immune and cognitive problems. The chief sources of B12, a water-soluble vitamin that is not stored in the body, are animal products, including meat, milk and eggs.
It remains uncertain whether vitamin B12 concentrations are a contributing factor to HIV progression or the result of the infection, the researchers said, but evidence from their study points to the former.