Implications of vitamin D deficiency in pregnancy and lactation

Abstract

Vitamin D is an essential fat soluble vitamin and a key modulator of calcium metabolism in children and adults. Because calcium demands increase in the third trimester of pregnancy, vitamin D status becomes crucial for maternal health, fetal skeletal growth, and optimal maternal and fetal outcomes. Vitamin D deficiency is common in pregnant women (5-50%) and in breastfed infants (10-56%), despite the widespread use of prenatal vitamins, because these are inadequate to maintain normal vitamin D levels (>or=32 ng/mL). Adverse health outcomes such as preeclampsia, low birthweight, neonatal hypocalcemia, poor postnatal growth, bone fragility, and increased incidence of autoimmune diseases have been linked to low vitamin D levels during pregnancy and infancy. Studies are underway to establish the recommended daily doses of vitamin D in pregnant women. This review discusses vitamin D metabolism and the implications of vitamin D deficiency in pregnancy and lactation.

FIGURE. Vitamin D metabolism and tissue actions

25(OH)D, 25-hydroxy vitamin D; Ca²⁺, calcium; CRP, C-reactive protein; DBP, vitamin D binding protein; DM, diabetes mellitus; MMP9, matrix metalloproteinase 9; PO4, phosphate; PTH, parathyroid hormone; SGA, small for gestational age; UVB, ultraviolet B.