NIH Study: Vitamin D May Reduce Risk of Uterine Fibroids
Uterine leiomyomata are leading cause of hysterectomy in U.S. (Apr. 15)
Women who had sufficient amounts of vitamin D were 32% less likely to develop fibroids than women with insufficient vitamin D, according to a study by researchers at the National Institutes of Health (NIH).
Fibroids, also known as uterine leiomyomata, are noncancerous tumors of the uterus. Fibroids often result in pain and bleeding in premenopausal women and are the leading cause of hysterectomy in the U.S.
The study involved 1,036 women aged 35 to 49 years living in the Washington, D.C., area from 1996 to 1999. The researchers screened participants for fibroids using ultrasound. They then used blood samples to measure 25-hydroxy D, the primary circulating form of vitamin D. Those with more than 20 ng/mL of 25-hydroxy D were categorized as “sufficient,” although some experts think even higher levels may be required for good health. The body can make vitamin D when the skin is exposed to the sun, or vitamin D can come from food and supplements.
The study participants also completed a questionnaire on sun exposure. Those who reported spending more than 1 hour outside per day also had a decreased risk of fibroids. The estimated reduction was 40%. Although fewer black than white participants had sufficient 25-hydroxy D levels, the estimated reduction in prevalence of fibroids was about the same for both ethnic groups.
“It would be wonderful if something as simple and inexpensive as getting some natural sunshine on their skin each day could help women reduce their chance of getting fibroids,” said Donna Baird, PhD, a researcher at the National Institute of Environmental Health Sciences (NIEHS), part of the NIH.
Baird is currently conducting a study in Detroit, Michigan, to see whether the findings from the Washington, D.C., study can be replicated. Other NIEHS in-house researchers are learning more about fibroid development by examining tissue samples from study participants who had surgery for fibroids.
Source: NIH; April 15, 2013.