Vitamin D may help treat uterine fibroids.
Uterine fibroids affect approximately 25 percent of women under the age of 30 and up to 40 percent of women older than 35, according to the Canadian Women’s Health Network. These benign tumors vary in size and in the symptoms they produce. Women can suffer from anemia due to very heavy menstrual bleeding, experience pain or be completely asymptomatic. This depends in part on the size and the location of the tumor. Very large tumors can cause additional symptoms if they begin to compress neighboring organs such as the digestive tract and the kidneys. The conventional treatments include hormone regulating medications such as GnRH agonists and progestin-based intrauterine devices, uterine artery embolization to reduce the bleeding, laparoscopic removal of the fibroid tissue and hysterectomy (removal of fibroid and uterus). Recurrence after surgery is not uncommon – whether by the development of a new fibroids or growth of residual fibroid tissue.
Skin cells produce vitamin D from cholesterol. This is dependent on sun exposure. It further metabolized by the liver and kidneys into an active form known as calcitriol. Dietary sources of vitamin D include cod liver, salmon, tuna, yogurt, liver, sardines, eggs and cheese. According to Osteoporosis Canada, the minimum daily intake of Vitamin D is 800 IU for an adult who is not deficient. However, if deficiency is present, they may require 2, 000 IU or more of vitamin D per day (while supervised by a licensed healthcare provider, such as a naturopathic doctor). While calcitriol is important for many different conditions, including anxiety, depression, osteoporosis, autoimmune disease, balance, and many others, this article will focus on its relationship to women’s health and fibroids.
Several observation studies report increased risk of fibroids associated with vitamin D deficiency. A study by Baird et al (2013) found that having sufficient levels of calcitriol reduced the odds of developing a fibroid by 32% percent. Spending more than one hour per day in the sun also correlated with protection against fibroids. In vitro (or test tube) studies show that vitamin D can interfere with the fibroids’ growth and limit the cell proliferation. Animal studies also demonstrate antitumor effect and report shrinkage of the fibroids.
A recent clinical trial by Ciavattini et al (2016) reports reduced progression of fibroid in the group of women who were supplemented with vitamin D compared to the control group. Both groups included women who were diagnosed with fibroids. The volume of fibroids was highest in the group of women who had the lowest amount of vitamin D. This was not a randomized study as the women self-selected whether they wanted to supplement with vitamin D or not. At the end of the study, more women in the control non-supplement group progressed to requiring surgery. Fewer women in the supplement group required surgical intervention. This is a small study involving only 208 women in total. It supports the pre-clinical data that suggest vitamin D is a reasonable treatment option in the management of uterine fibroids.
For additional treatments of fibroids see Acupuncture Treatment for Heavy Bleeding in Fibroids.
Baird et al. Vitamin D and risk of uterine fibroids. Epidemiology. 2013; 24(3): 447-453