Vitamin D deficiency in a healthy group of mothers and newborn infants.

Plasma 25-hydroxyvitamin D was measured in 40 healthy, mostly Black, mother-infant pairs. Although a majority of mothers received a daily prenatal multivitamin, vitamin D deficiency (<30 nmol/L), was found in 50% of mothers and 65% of their newborn infants, with a positive correlation between maternal and infant plasma 25-hydroxyvitamin D concentrations. Maternal vitamin D deficiency may represent an important risk factor for the development of rickets in children.