Vitamin A supplementation and human immunodeficiency virus load in injection drug users.

Randomized, double-blind, placebo-controlled clinical trial in HIV-seropositive injection drug users enrolled in the ALIVE cohort in Baltimore, United States. Sixty participants were randomized to the vitamin A arm, and outcomes were assessed at baseline and again 2 and 4 weeks after treatment.

Vitamin A was given as a single oral high dose of 60 mg retinol equivalent (200,000 IU) as retinol capsules. The active arm was compared with identical placebo capsules.

Vitamin A supplementation did not significantly reduce HIV load or improve CD4 lymphocyte count over 2 and 4 weeks, so the intervention was not effective for the main HIV-related outcomes. Log HIV load was similar between groups at baseline (P=.14) and at both follow-up visits (P=.17), and the mixed-model treatment effect on HIV load was not significant (b=.004, P=.96). CD4 counts also showed no between-group differences at baseline or follow-up. Plasma vitamin A levels increased relative to placebo, with a significant treatment effect at follow-up (P=.01), but this biochemical change did not translate into an HIV load benefit.

Follow-up was very short, with only 2- and 4-week assessments after a single dose, so longer-term effects were not tested. The population was specific to HIV-infected injection drug users in Baltimore, limiting generalizability. The active-arm sample was modest, and the study was not designed to detect small clinical changes in HIV outcomes.