Is Vitamin D Effective in the Treatment of Uterine Leiomyoma? A Randomized Controlled Double-Blind Clinical Trial

Abstract

Objectives: Recent studies have shown that vitamin D deficiency is more common in women with uterine leiomyomas than in healthy women. Molecular investigations have also confirmed the role of vitamin D in the pathogenesis of uterine leiomyoma. The aim of the present study was to evaluate whether vitamin D administration is effective in the treatment of leiomyoma in patients suffering from vitamin D deficiency. Methods: This is a double-blind clinical trial (registration No. IRCT2014121511019N4). Fifty one women diagnosed with uterine leiomyomas who were also suffering from vitamin D deficiency were randomly divided into two groups: the intervention group (n = 26) and the control group (n = 25). The intervention group received vitamin D3 following the guidelines provided by an endocrinologist, while the control group received placebo. For each group, changes in the size of leiomyoma were measured. Furthermore, before the start of treatment and two and four months into the treatment, menstrual blood loss volume was assessed using the pictorial blood loss assessment chart (PBAC), pelvic pain was assessed by visual analogue scale (VAS), and serum hemoglobin level was also determined. These measurements were compared between the two groups. Results: At the baseline, the median of the total volume of leiomyoma in the intervention and control groups was 731.8 and 440.5 cm3, respectively. After four months of treatment, the aforementioned values were 691.1 and 404.9 cm3, indicating a significantly greater decrease in the volume of leiomyoma in the intervention group than in the control group (P = 0.014). The intervention group showed a significantly greater decrease in PBAC than the control group (P = 0.02). However, there were no significant differences between the two groups in the pain or menstrual blood loss indices. Conclusions: We conclude that the treatment of vitamin D deficiency in patients with uterine leiomyoma may reduce the size of leiomyoma.