To determine whether specific nutrient abnormalities occur in earlier stages of HIV-1 infection, thereby preceding the marked wasting and malnutrition that accompany later stages of the infection. A longitudinal investigation to determine biological, psychological and social factors thought to influence the progression and outcome of HIV-1 infection. Nutritional status was assessed using biochemical measurement of nutrient levels, dietary history, anthropometry and clinical examination for the signs and symptoms of nutritional deficiency or excess. The study was performed on an outpatient basis at the University of Miami School of Medicine. One hundred homosexual men, aged between 20 and 55 years, who were asymptomatic other than persistent generalized lymphadenopathy (Centers for Disease Control stage III) and 42 age-matched homosexual men demonstrated to be free of HIV-1 infection at two 6-month intervals. Biochemical measurement of nutrient status, dietary history, anthropometry, clinical signs or symptoms of nutritional excess or deficiency were obtained for all participants. Despite few differences in mean blood levels of specific nutrients, prevalence of specific nutrient abnormalities was widespread among HIV-1-infected subjects, compared with non-infected male homosexual controls. Overtly and marginally low blood levels of vitamins A (18%), E (27%), riboflavin (26%), B6 (53%), and B12 (23%), together with copper (74%) and zinc (50%) were documented in HIV-1-seropositive subjects. With the exception of riboflavin, zinc, and copper, a similar prevalence of abnormalities among HIV-1-seronegative controls was not observed. Specific nutrient abnormalities occur with relative frequency in asymptomatic HIV-1 infection and may contribute to the rate and form of HIV-1 disease progression.