What makes one person with HIV stay well longer than another? Gene mutation? Viral strain? A new study says vitamin B-12 may play a role. Johns Hopkins University researchers have found that of 310 HIV positive gay and bisexual men, those with adequate B-12 levels did not progress to AIDS for about eight years, compared to only four years for those deficient. No benefits were seen in the few with surplus B-12. Dr. Alice Tang, who led the study, called for trials to confirm the link and to “see if improvement in the levels of nutrients like B-12, with vitamin supplements, improves outcome.” B-12 is found in such animal products as meat, eggs and milk.