Uterine fibroids are the most common non-cancerous tumours in women of childbearing age that often result in pain and bleeding in premenopausal women.
However, new data from the US National Institutes of Health (NIH) suggests that having an adequate intake of vitamin D may be shrunk the risk of developing the common problem by almost a third.
"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 Dr Donna Baird from the US National Institute of Environmental Health Sciences (NIEHS).
The human body can make vitamin D when the skin is exposed to the sun, or vitamin D also be consumed in food and nutritional supplements, the authors noted.
The study, published in the journal Epidemiology, of 1,036 women, aged 35-49, used blood samples to measure the primary circulating form of vitamin D, known as 25-hydroxy D. Those with more than 20 nanograms per milliliter of 25-hydroxy D – referred to as 25(OH)D – were categorized as sufficient, though some experts think even higher levels may be required for good health.
Baird and her collaborators then screened participants for fibroids using ultrasound.
Women who had sufficient amounts of vitamin D were 32% less likely to develop fibroids than women with insufficient vitamin D, they said.
Study participants also completed a questionnaire on sun exposure, with the team finding that those who reported spending more than one hour outside per day also had a decreased risk of fibroids – estimated to be at about 40%.