Vitamin D supplementation in pregnancy, lactation and infancy: why is it fundamental?

Abstract

Vitamin D is mainly made in the skin following exposure to sunlight but can also be taken in via specific natural or fortified food sources. It is essential for intestinal calcium absorption and thereby bone mineralisation. Deficiency in vitamin D, or low dietary calcium intake, therefore results in defective bone mineralisation causing osteomalacia in children and adults and rickets in growing children. The leading causes of rickets and osteomalacia worldwide are solar vitamin D deficiency and/or nutritional calcium deficiency. Long-standing severe vitamin D deficiency can lead to craniotabes, large fontanelle, leg bowing, stunted growth and obstructed labour. The deficient state in the infant is almost always acquired from the mother. Therefore, robust antenatal and infant vitamin D supplementation programmes are obligatory to prevent complications. Conversely, lack of programme monitoring and conflicting recommendations can lead to confusion among healthcare professionals and poor uptake in the population. Factors shown to improve adherence to supplementation include universal supplementation of breast- and bottle-fed infants, monitoring supplementation at antenatal/postnatal healthcare visits, providing information to families at discharge from the neonatal unit and financial family support.