Vitamin D study in pregnant women and their babies

Vitamin D deficiency is very common in pregnant women. Deficiencies have been prevalent even in studies where over 90% of the women took prenatal vitamins. The current guidelines for vitamin D intake during pregnancy of 200-400 IU has little scientific support and has been recently challenged. We conducted this study to determine the prevalence of vitamin D deficiency among pregnant women and to evaluate the effectiveness and level of weekly oral 50,000 IU of vitamin D supplementation for the mother and the newborn.

Prospective study at Hamad Medical Corporation outpatient unit and delivery room.

Ninety seven pregnant women were recruited in their first trimester between December 2007 and March 2010. Weekly oral vitamin D (50,000 IU) were prescribed after an initial testing for serum level of 25-hydroxyvitamin D, parathyroid hormone, calcium, phosphorus, total protein and albumin. Other multivitamins supplementations were allowed during pregnancy. The same tests were repeated at each trimester. Umbilical cords vitamin D levels were determined at birth.

Out of 97 patients, 8 patients dropped out from the study for several reasons, and 19 patients had pregnancy loss. Data were available for 97 women in the first trimester, 78 women in the second trimester and 61 women in the third trimester. The mean level of vitamin D level in the first trimester and prior to starting vitamin D supplementation was 17.15 ng/ml, 29.08 ng/ml in the second trimester, 27.3 ng/ml in third trimester and 22.36 ng/ml in newborns. There were no toxic levels of vitamin D in any of the women at the second or third trimesters or in the newborns. The mean levels of vitamin D in the second and third trimester were not significantly different in those women who were taking multivitamin supplementation and those who were not.

Weekly doses of 50,000 vitamin D during pregnancy maintains acceptable vitamin D level during pregnancy and the newborn's vitamin D level correlates with the mother's levels.