Vitamin D deficiencies widespread among pregnant women and infants despite prenatal vitamin usage

Vitamin D deficiency early in life is associated with rickets, a disorder characterized by soft bones. New research has shown that despite taking a prenatal vitamin, vitamin D deficiency is very common in pregnant women and newborn infants. Higher-dose supplementation and increased sun exposure is needed to improve maternal and infant vitamin D status.

Even among those taking prenatal multivitamin supplements, vitamin D levels were found to be insufficient or deficient in pregnant women, particularly in African-American women and women living in northern regions, according to new research published in the Journal of Nutrition. Researchers took blood samples from 400 pregnant women - 200 black women and 200 white women - before 22 weeks gestation and again after delivery.

More than 80% of African American women and nearly half of white women tested at delivery had levels of vitamin D that were insufficient, even though more than 90% of them used prenatal vitamins during pregnancy.

In addition, umbilical cord blood from newborns showed 92.4% of African American babies and 66.1% of white infants had insufficient vitamin D levels at birth, leaving them at risk for rickets and other health problems. A newborn relies completely on its mother for its vitamin D stores.

These results suggest that black and white pregnant women and newborns residing in the northern US are at high risk of vitamin D insufficiency, even when mothers regularly take prenatal vitamins. Higher-dose supplementation is needed to improve maternal and infant vitamin D status.

J. Nutr. 137:447-452, February 2007