Effect of Oral Consumption of Vitamin D on Uterine Fibroids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Abstract

Impaired vitamin D status is highly prevalent among women with UFs. The objective of this first-ever systematic review and meta-analysis was to summarize the effect of vitamin D supplementation on the size of uterine fibroids (UFs). We performed a comprehensive literature search for published randomized controlled trials (RCTs) in Medline, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials from inception to September 2022. Five trials including 511 participants (256 cases and 255 controls) were included. Pooling results from five trials, which compared size of UFs between experimental and placebo groups, revealed that vitamin D supplementation could significantly decrease the size of UFs (standardized mean difference [SMD]: −0.48, 95% confidence interval [CI]: −0.66, −0.31) and cause improvement in serum level of vitamin D compared to placebo group (SMD: 3.1, 95% CI: 0.66, 5.55). A significant effect was observed in the subset of trials administering vitamin D supplementation for >8 wk (SMD: −0.62, 95% CI: −0.88, −0.37). In conclusion, vitamin D supplementation significantly increases serum levels of vitamin D and reduces the size of UFs. However, larger, well-designed RCTs are still needed to determine the effect of vitamin D on other parameters of UFs.

Authors’ Contributions

SAA and AA-Z contributed to study conception, data analysis, study supervision, and manuscript writing. SB, MSA, KK, RA, EB, IAB, AA, AMK, and OA contributed to literature review, data collection, data interpretation, and revision of manuscript for editorial and intellectual contents. All authors read and approved the final draft of the manuscript.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Data Availability Statement

All data are presented within the manuscript and its supplementary files.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.