Uterine fibroids, noncancerous tumors of the uterus that often cause pain and bleeding in premenopausal women and are the leading cause of hysterectomy in the United States, are less likely to develop in women with enough vitamin D in their system, a new study finds.
The study, by researchers at the National Institute of Environmental Health Sciences (NIEHS), included more than 1,000 women, aged 35 to 49. Those with sufficient amounts of vitamin D were 32 percent less likely to develop uterine fibroids than those with insufficient vitamin D levels.
The researchers also found that women who spent more than an hour outside per day had a 40 percent decreased risk of fibroids. The body makes vitamin D when the skin is exposed to sunlight. Vitamin D also comes from food and supplements.