Access to Highly Active Anti-Retroviral Therapy (HAART) for the treatment of HIV in developing regions is limited, but gradually becoming standard of care in some countries. Multivitamin supplements have demonstrated immune-enhancing effects among individuals in pre-HAART HIV disease stages. However, the efficacy and safety of micronutrient supplements need to be documented in the context of HAART. This study is a double-blind randomized clinical trial, conducted to examine the effect of multivitamins (including B, C, and E) on HIV disease progression among individuals taking HAART. Participants are HIV-positive Tanzanian men and women aged 18 years and older, who are initiating HAART at the time of randomization. Eligible individuals are randomized to receive daily oral supplements in one of two intervention groups: a) multivitamins at the single Recommended Dietary Allowance (RDA) level; and b) multivitamins at multiples of the RDA at the same doses used in our previous study "A Trial of Vitamins in HIV Progression and Transmission".