Vitamin D During Pregnancy and Infant Growth: A Long Shot

Investigators from multiple institutions conducted a randomized controlled trial to determine the efficacy of maternal vitamin D supplementation (VDS) on infant growth in regions where vitamin D deficiency is common. Participants were healthy pregnant women living in Bangladesh who were 17–24 weeks’ gestation. At enrollment, participants were randomized to 1 of 5 groups, based on receipt of (a) a placebo tablet through the prenatal period and for 26 weeks postpartum, (b) prenatal VDS only at 4,200 IU/week, (c) prenatal VDS only at 16,800 IU/week, (d) prenatal VDS only at 28,000 IU/week, and (e) prenatal VDS at 28,000 IU/week and postpartum VDS at 28,000 IU/week for 26 weeks. All tablets were identical in taste and appearance, and they were administered under direct observation when possible. …