Effects of Vitamin D Supplementation During Pregnancy on Clinical Outcomes and Immune Function

Researchers at the USDA Western Human Nutrition Research Center and clinicians at UC Davis
Medical Center are currently conducting a study on the effects of vitamin D supplementation
during pregnancy on maternal health and immune function. The investigators believe that
vitamin D supplementation at levels greater than the current recommendation is beneficial
for maternal health during pregnancy. In particular, there is evidence that vitamin D
deficiency during pregnancy puts women at greater risk for diseases like pre-eclampsia,
which may be due to an imbalance in immune function at the placenta. This randomized,
double-blind study is designed to test this hypothesis. Pregnant women who participate in
the study receive either 400 IU or 2,000 IU of vitamin D per day for the duration of their
pregnancy. The investigators will collect blood at three time points during pregnancy (16-20
weeks, 26-28 weeks, 36 weeks gestation) for analysis of immune function and vitamin D
status. The investigators are also collecting data on clinical parameters, such as blood
pressure and glucose tolerance.