Randomized, double-blind, placebo-controlled trial of selenium supplements among HIV-infected pregnant women in Tanzania: effects on maternal and child outcomes.

Randomized, double-blind, placebo-controlled trial among HIV-infected pregnant women in Dar es Salaam, Tanzania, enrolled at 12-27 weeks' gestation and followed through 6 months postpartum. The selenium group included 457 participants and the placebo group 456 participants.

Daily oral selenium supplementation as selenomethionine, given from enrollment in mid-pregnancy until 6 months postpartum, was compared with placebo. The extracted dose was 200 micrograms of elemental selenium daily.

Selenium supplementation did not improve maternal HIV disease markers or most pregnancy outcomes, but it was associated with lower infant death. Follow-up showed no significant effect on CD4, CD3, or CD8 counts or viral load (P=0.72, 0.86, 0.91, and 0.71, respectively), and no meaningful difference in birth weight (3008 vs 2982 g; P=0.76), gestational age at delivery (39.3 vs 39.4 weeks; P=0.87), or small for gestational age (18.4% vs 17.5%; RR 1.10, 95% CI 0.81-1.49). Infant death was lower in the selenium group, 8 (2.2%) vs 19 (5.0%) (RR 0.43, 95% CI 0.19-0.99; P=0.048), but neonatal or infant death was not statistically significant (RR 0.64, 95% CI 0.36-1.13; P=0.12). Overall, the authors concluded there was no support for routine selenium supplementation under these study conditions.

Interpretation is limited by the study context of concurrent high-dose multivitamin use and low likelihood of baseline selenium deficiency, which may reduce generalizability. Several outcomes were null and the mortality finding was based on relatively few events, so the apparent infant survival benefit should be viewed cautiously.