Selenium deficiency may increase risks of anemia and morbidity among people with human immunodeficiency virus infection. We therefore investigated the effect of selenium supplements (200 microg of selenomethionine) on these end points among 915 pregnant Tanzanian women. Hemoglobin concentration was measured at baseline (at 12-27 weeks of gestation) and at 6 weeks and 6 months postpartum, and morbidity data were collected during monthly visits to the clinic. Selenium supplements had no effect on hemoglobin concentrations during follow-up (mean difference, 0.05 g/dL; 95% confidence interval, -0.07 to 0.16 g/dL) but reduced diarrheal morbidity risk by 40% (relative risk, 0.60; 95% confidence interval, 0.42-0.84). There was no effect on the other morbidity end points.
Trial registration: ClinicalTrials.gov NCT00197561.