© chompoo / stock.adobe.com BMC Pregnancy and Childbirth – Effect of early vitamin D supplementation on the incidence of preeclampsia in primigravid women: a randomised clinical trial in Eastern Democratic Republic of the Congo Preeclampsia (PE) is a hypertensive disorder of pregnancy that affects around 5% of pregnant women globally and it can bring to preterm delivery, low birth weight and even to the death of the mothers and their newborns.