Vitamin D Treatment Shrinks Mammalian Fibroid Tumors

Uterine fibroid tumors, the most common problematic benign tumors in women of childbearing age, were greatly reduced upon treatment of laboratory rats with vitamin D.

Uterine fibroids are associated with infertility, miscarriage, and preterm labor. Thirty percent of women 25 to 44 years of age report fibroid-related symptoms, such as lower back pain, heavy vaginal bleeding, or painful menstrual periods. Compared to white women, these tumors are 3-4 times more common in African-American women, who also have a roughly ten times higher incidence of vitamin D deficiency.

Other than surgical removal of the uterus, there are few treatment options for women experiencing severe fibroid-related symptoms and about 200,000 US women undergo the procedure each year.

On March 1, 2012, the National Institutes of Health (NIH; Bethesda, MD, USA) released a report summarizing the study published in the journal Biology of Reproduction, in which researchers tested a three-week, subcutaneous vitamin D treatment regimen on a strain of female rats genetically predisposed to developing the fibroid tumors (formally, uterine leiomyoma tumors).

First author Sunil K. Halder, PhD, of Meharry Medical College (Nashville, TN, USA) conducted the research with coauthors and Meharry colleagues Chakradhari Sharan, PhD, and Ayman Al-Hendy, MD, PhD, and with Kevin G. Osteen, PhD, of Vanderbilt University Medical Center (Nashville, TN, USA).

In previous work, the study authors found that vitamin D inhibited the growth of human fibroid cells in laboratory tissue cultures. This provided a lead to the current study on rats, the results of which “provide a promising new lead in the search for a nonsurgical treatment for fibroids that doesn't affect fertility," said Louis De Paolo, PhD, chief of the Reproductive Sciences Branch of the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD; Bethesda, MD, USA), which funded the study.

After examining the animals and confirming the presence of the fibroids in 12, the researchers divided the rats into two groups of six each: those that would receive vitamin D (formally, 1,25-dihydroxyvitamin D3) and the control group of those that would not. In the first group, small pumps implanted under the skin delivered a continuous dose of vitamin D for three weeks. Fibroids increased in size in the untreated rats, but, in the rats receiving vitamin D, the tumors had shrunk dramatically.

Toxicity analyses testing indicators in serum showed similar levels in vitamin D-treated and control groups, supporting that vitamin D may be a potentially safe, nonsurgical therapeutic option for the treatment of uterine leiomyomas.

Related Links:
National Institutes of Health
Eunice Kennedy Shriver National Institute of Child Health and Human Development
Meharry Medical College