Abstract
During pregnancy, the fetus is entirely dependent on maternal sources of vitamin D, which also regulates placental function. Vitamin D deficiency during pregnancy has been associated with intrauterine growth restriction (IUGR). This study aims to provide a narrative review of the potential influence of vitamin D deficiency on the pathogenesis of IUGR, and the potential benefits of vitamin D supplementation during pregnancy on fetal anthropometry. This review highlights the high prevalence of vitamin D deficiency among pregnant women and newborns worldwide, even in sunny countries. Most studies support that fetal vitamin D levels are directly related to maternal vitamin D levels. There is extensive literature confirming the relation between maternal vitamin D status and fetal growth patterns throughout pregnancy (both early and late). However, there is currently insufficient evidence to establish recommendations on optimal prenatal vitamin D supplementation in women to reduce the risk of IUGR.