An adequate vitamin D supply may reduce the risk of uterine fibroids

Women who have sufficient blood vitamin D concentrations are 32% less likely to develop fibroids (non-cancerous tumors of the uterus) than women with insufficient levels, suggests a new US study.

This observational study measured plasma 25-hydroxyvitamin D concentrations of 1,036 women, aged 35 to 49, and screened participants for fibroids using ultrasound (1). The study results showed that the participants with more than 20 nanograms per milliliter of 25(OH)D had a 32% risk reduction of developing fibroids. Women who reported spending more than one hour outside per day also had a decreased risk of fibroids – the estimated reduction was 40%. Although fewer black participants had sufficient 25(OH)D levels than white participants, the estimated reduction in the prevalence of fibroids was about the same for both ethnic groups.

The researchers commented that the study would be added to a growing body of literature showing the be-nefits of vitamin D. Though the findings are consistent with laboratory studies, more studies on women are needed. By examining tissue samples from study participants who have had surgery for fibroids, for examp-le, the scientists hope to learn more about fibroid development, which is the leading reason for performing an operation to remove a woman’s uterus (hysterectomy) in the United States.

1. Baird D. D. et al. Vitamin D and the risk of uterine fibroids. Epidemiology. Published online April 2013.