Subramanian A, Korsiak J, Murphy KE, et al. - Researchers here investigated the dose-dependent effect of maternal vitamin D during pregnancy on blood pressure from mid-to-late gestation via performing a randomized, placebo-controlled trial of vitamin D supplementation in Bangladesh (n = 1,298). They enrolled healthy women without hypertension at 17–24 weeks gestation and randomly assigned them to one of the four vitamin D doses during pregnancy: placebo, 4200, 16 800 or 28 000 IU/week. No effect of vitamin D supplementation starting mid-pregnancy was noted on SBP or DBP until late gestation; blood pressure was higher at 36 weeks for the highest dose vs placebo. Results thereby provide no support for the clinical use of vitamin D in pregnancy to lower maternal blood pressure.