Vitamin D to combat preterm birth

Infections involving the uterus and placenta are a leading cause of preterm birth, especially the earliest ones that pose the biggest risk to the baby. Because most pregnant women will experience no symptoms until they go into early labor, the infections are difficult to diagnose and treat. Martin Hewison, PhD, a March of Dimes Prematurity Research Initiative grantee at the University of California in Los Angeles, is investigating whether vitamin D can stimulate the immune system to fight off infections and help prevent preterm birth.

“Preterm birth is a particular problem for African-American mothers. Compared to caucasian mothers, they are almost twice as likely to deliver early,” says Dr. Hewison. African-American women also are more likely to have low levels of vitamin D in their blood, at least in part because people with darker skin filter more sunlight, which is required for the conversation of the inactive provitamin to the active form of the vitamin. Adding vitamin D to the diets of African-American moms-to-be may be beneficial. Because vitamin D is toxic in excessive doses, this should be done cautiously.

“Our preliminary data suggest that vitamin D fulfills a unique function in pregnancy by both enhancing bacterial killing and suppressing associated inflammation,” says Dr. Hewison. Uterine inflammation, which often results from infection, appears to play an important role in triggering preterm labor. If the results of his study are confirmed, his ultimate goal is to develop cheap and effective vitamin D supplementation regimens that could help prevent infection-related preterm deliveries in African-American moms-to-be and other pregnant women.