Micronutrient deficiencies are common in HIV/AIDS, resulting from both malabsorption and virally-caused depletion. Beta carotene and selenium deficiencies, two of the most common nutrient deficiencies, are important due to their dual function as nutrients necessary for immune modulation and as antioxidants. Beta carotene deficiencies are common in all stages of HIV/AIDS and may signal malabsorption. Supplementation has been shown to affect specific T lymphocyte populations and decrease markers of lipoperoxides. Selenium levels are highly significant in predicting AIDS-related mortality; and the HIV virus manufactures selenoproteins that are involved in the regulation of viral replication, possibly depleting host levels of selenium. Supplementation trials with individual antioxidants have shown improvement in immunological parameters and decreased evidence of lipid peroxidation.