Skip to main content
Department of Obstetrics and Gynecology

Department of Obstetrics and Gynecology

Inflammation and Pregnancy Outcomes in Women at Risk of Vitamin D Deficiency

Principal Investigator: Professor Dena Towner, M.D.

Co-PI: Associate Physician Bryon Jacoby, M.D.

Research Funding: UC Davis Board of Advisors


Women of childbearing age are at risk of vitamin D deficiency (VDD) because of low sun exposure, low dietary intake of vitamin D and, in the case of some minority populations, dark skin pigmentation. While the major, long-term risks of VDD for these women are well known (i.e., loss of bone mineral density) recent studies suggest that VDD in pregnancy may increase the risk of inflammation-related adverse events, including preeclampsia. In utero VDD also increases the risk of rickets in infants and may also increase the risk of subsequent immune-mediated disease (e.g., risk of type I diabetes and other autoimmune disease) for these infants. The current recommended adequate intake for vitamin D for pregnant women is 200 IU/d although for women without significant sun exposure, this dietary intake will not be sufficient to maintain adequate vitamin D status. We propose to conduct a randomized, controlled trial of vitamin D supplements in women at risk of vitamin D deficiency (based on their reported dietary intake, sun exposure and level of skin pigmentation) to determine if vitamin D supplementation decreases the level of inflammation during the second and third trimesters and decreases the risk of adverse clinical outcomes, including impaired glucose tolerance, preterm delivery, and the risk of pregnancy-related hypertensive disorders. As increasing evidence has linked poor obstetric outcomes and increased maternal and neonatal morbidity to vitamin D deficient states, such an intervention is timely and a logical progression of the large amount of literature suggesting the need for refinement of current recommendations in pregnancy. It also represents a simple intervention that could potentially be useful throughout the developing world, where pregnancy-related hypertensive disease is one of the leading causes of maternal and neonatal mortality. We propose to recruit pregnant women at <20 weeks gestation who are at risk of VDD using our diet and sun exposure recall questionnaires and skin reflectance. Serum 25(OH)D and markers of inflammation will be measured at certain intervals during gestation, and then analyzed when all subjects have completed the study to determine baseline status and response to treatment. Patients will be followed clinically and clinical outcomes, including glucose intolerance, hypertensive disorders of pregnancy, preterm delivery, and birthweight, will be assessed. Prenatal data will be collected in an ongoing manner, and analyzed at the completion of the study.