Infant and fetal vitamin D status and bone health

Abstract

Recently, considerable interest has been shown in the role of maternal vitamin D status on growth, bone development and mineral homeostasis of the developing fetus, infant and child, especially in view of our better understanding of the possible long-term effects of impaired early growth and development on body composition and bone mass in later life. Although the fetus is to a large extent well protected against the possible deleterious effects of maternal vitamin D deficiency, there is evidence that maternal vitamin D deficiency might result in impaired fetal mineralization and growth. Further maternal vitamin D deficiency increases the risk of neonatal hypocalcaemia and its complications during the first month of life. Maternal vitamin D deficiency is a major risk factor for vitamin D deficiency rickets in the breastfed infant, and thus attention should be paid to ensuring maternal vitamin D sufficiency during pregnancy and preventing vitamin D deficiency in the infant through either maternal or infant vitamin D supplementation. The long-term consequences of maternal vitamin D deficiency during pregnancy are not clearly defined, although some studies have suggested impaired growth during infancy and reduced bone mass in pre-pubertal children. Further research is required to unravel the role of maternal vitamin D not only on children's bone mass and growth but also on the possible non-skeletal effects of vitamin D. The importance of ensuring vitamin D sufficiency in the breastfed infant and methods of achieving this are discussed, and the recently released recommendations of the Institute of Medicine with regard to recommended dietary allowances for vitamin D are placed in context.