Vitamin D may prevent uterine fibroids tumors from developing in women. (Lack of uteri prevent them from developing in men). A new study from the National Institute of Environmental Health Sciences (NIEHS) found that women who had sufficient amounts of vitamin D in their systems were significantly less likely to develop fibroids than women with insufficient vitamin D, reports

Fibroids are growths in the uterus that occur in three out of four women during their childbearing years, according to the Mayo Clinic. Most women are unaware of the fibroids, as they usually have no symptoms. For some women, however, they can cause severe pain. They are the leading cause of hysterectomy in American women, according to an NIEHS release about the study.

NIEH researcher Donna Baird led the project with colleagues at The George Washington University and the Medical University of South Carolina. They ultrasounded 1,036 women between the ages of 35 and 49 living in the Washington, D.C. Area in search of fibroids. They used blood samples to measure levels of 25-hydroxy D, which is the primary circulating form of vitamin D. The body creates vitamin D when the skin is exposed to the sun. The vitamin can also be consumed in dietary supplements and foods. Researchers considered 20 nanograms per milliliter of 25-hydroxy D sufficient.

Women who had sufficient amounts of vitamin D were 32 percent less likely to develop fibroids than women with insufficient vitamin D.

The research team also asked participants about their level of sun exposure. Women who spent more than an hour outside each day also had a decreased risk of fibroids, a reduction of about 40 percent.

“This study adds to a growing body of literature showing the benefits of vitamin D,” said Linda Birnbaum, Ph.D., director of NIEHS and the National Toxicology Program in the release. The study will appear in the journal Epidemiology.