A randomized trial to determine the optimal dosage of multivitamin supplements to reduce adverse pregnancy outcomes among HIV-infected women in Tanzania

Abstract

Background: We previously reported that supplementation with multivitamins (vitamin B complex, vitamin C, and vitamin E) at multiples of the Recommended Dietary Allowance (RDA) significantly decreased the risk of adverse pregnancy outcomes among HIV-infected women. The minimum dosage of multivitamins necessary for optimal benefits is unknown. Objective: We investigated the efficacy of multivitamin supplements at single compared with multiple RDAs on decreasing the risk of adverse pregnancy outcomes among HIV-infected women. Design: We conducted a double-blind, randomized controlled trial among 1129 HIV-infected pregnant women in Tanzania. Eligible women between 12 and 27 gestational weeks were randomly assigned to receive daily oral supplements of either single or multiple RDA multivitamins from enrollment until 6 wk after delivery. Results: Multivitamins at multiple and single doses of the RDA had similar effects on the risk of low birth weight (11.6% and 10.2%, respectively; P = 0.75). We found no difference between the 2 groups in the risk of preterm birth (19.3% and 18.4%, respectively; P = 0.73) or small-for-gestational-age (14.8% and 12.0%, respectively; P = 0.18). The mean birth weights were similar in the multiple RDA (3045 ± 549 g) and single RDA multivitamins group (3052 ± 534 g; P = 0.83). There were no significant differences between the 2 groups in the risk of fetal death (P = 0.99) or early infant death (P = 0.19). Conclusion: Multivitamin supplements at a single dose of the RDA may be as efficacious as multiple doses of the RDA in decreasing the risk of adverse pregnancy outcomes among HIV-infected women. This trial was registered at clinicaltrials.gov as NCT00197678. © 2010 American Society for Nutrition.