This study evaluated blood levels of vitamin B12 in patients with acquired immunodeficiency syndrome (AIDS). 11 patients with AIDS and vitamin B12 malabsorption (poor intestinal absorption of vitamin B12) were investigated. In addition, 15% of 121 patients with AIDS and 7% of 27 patients without AIDS who were HIV-positive had low vitamin B12 levels. The results showed that vitamin B12 malabsorption is common in patients with AIDS and may be a very early manifestation of infection with HIV. Further details can be found in the study.
G R Harriman, P D Smith, M K Horne, C H Fox, S Koenig, E E Lack, H C Lane, A S Fauci