Vitamin D supplementation during pregnancy for the prevention of pre-eclampsia
Vitamin D is known to play an important role in bone metabolism through regulation of calcium and phosphate equilibrium. Vitamin D is produced by the body during exposure to sunlight, but is also found in oily fish, eggs and fortified food products.
Vitamin D deficiency is thought to be common among pregnant women in some populations, and has been found to be associated with an increased risk of pre-eclampsia, gestational diabetes mellitus, preterm birth, and other tissue-specific conditions.
Hypertensive disorders* such as pre-eclampsia and eclampsia are among the main causes of maternal deaths and preterm births, especially in low-income countries. Preterm births are the leading cause of early neonatal deaths and infant mortality, and survivors are at higher risk of respiratory disease and long-term neurological morbidity.
Vitamin D supplementation in pregnancy improves maternal vitamin D status and may therefore be expected to reduce the risk of pre-eclampsia, however limited evidence indicates that vitamin D supplementation does not reduce the risk of pre-eclampsia.
*disorders in which blood pressure is elevated
Vitamin D supplementation is not recommended during pregnancy to prevent the development of pre-eclampsia and its complications.
Additional information can be found in the guidance summary, and in the guideline under 'WHO documents' below.
Vitamin D supplementation in pregnant women
WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia