Are multiple RDA multivitamin doses more effective than a single RDA for improving HIV-positive women’s pregnancy outcomes?

February 2010

In a study published in February 2010 in the American Journal of Clinical Nutrition, investigators compared the efficacy of multivitamin supplements delivering a single recommended daily allowance (RDA) versus supplements delivering multiple RDAs in improving pregnancy outcomes of HIV-positive women in Tanzania. Results from an earlier randomized trial in Tanzania by the same authors had shown that supplementation of HIV-positive pregnant women with multivitamins (B complex, C, and E) at levels many times that of the RDA decreased the risk of several adverse pregnancy outcomes.  This trial randomized pregnant, HIV-infected women into two groups receiving a daily oral dose of a single RDA or multiple RDA multivitamin for an average of 3.9 months during gestation and 5.1 weeks postpartum. Adherence in both groups was greater than 85%. An intent-to-treat analysis showed no difference between the groups on all of the studied outcomes, including low birth weight, smallness for gestational age, fetal death, risk of miscarriage or stillbirth, and risk of perinatal or early infant death.

The incidence of adverse outcomes in both groups was similar to that found in the authors’ previous multiple-RDA study, suggesting that both the single- and multiple-RDA interventions of this study were effective. However, the investigators point out that some studies of multiple micronutrient supplementation in pregnancy have suggested that they may elevate perinatal mortality, and that multivitamin supplements should only be given where adequate antenatal and obstetric care is available. They conclude that these findings add to the results of many other studies indicating that HIV-infected pregnant women should receive at least a daily single RDA multivitamin. 

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