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

Assessment of Inflammatory Markers and Pregnancy Outcomes in Vitamin D-Supplemented Women at Risk of Vitamin D Deficiency: A Double-Blind, Randomized Controlled Trial

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.

Women in this study arm receive 400 IU of vitamin D3 per day, or what is in a standard prenatal multivitamin. They also receive a placebo study supplement.

Women in this arm receive 2,000 IU vitamin D per day: 400 IU from a standard prenatal multivitamin plus an additional 1,600 IU vitamin D3 in the study supplement.

Women in this study arm receive 400 IU of vitamin D3 per day, or what is in a standard prenatal multivitamin. They also receive a placebo study supplement.

Women in this arm receive 2,000 IU vitamin D per day: 400 IU from a standard prenatal multivitamin plus an additional 1,600 IU vitamin D3 in the study supplement.

Monocyte and NK cell cytokine expression and response to stimulation with Toll-like Receptor agonists.

Inclusion Criteria: Pregnant women Less than 20 weeks gestation Over 18 years of age Able to swallow nutritional supplements Exclusion Criteria: Use of medications known to affect vitamin D metabolism Diagnosis of type 1 diabetes History of thyroid, renal, or liver disease Problems with digestion or absorption

Zerofsky MS, Jacoby BN, Pedersen TL, Stephensen CB. Daily Cholecalciferol Supplementation during Pregnancy Alters Markers of Regulatory Immunity, Inflammation, and Clinical Outcomes in a Randomized Controlled Trial. J Nutr. 2016 Nov;146(11):2388-2397. doi: 10.3945/jn.116.231480. Epub 2016 Sep 21.