The Effect of Vitamin D Deficiency and Supplementation on Urinary Incontinence: Scoping Review

Introduction and hypothesis: Vitamin D receptors are found in skeletal and smooth muscle cells throughout the body, specifically in the bladder detrusor muscle. We reviewed the current literature on the association between vitamin D deficiency and urinary incontinence (UI), and whether vitamin D supplementation plays a role in the treatment of UI symptoms. Methods: We performed a scoping review of all available studies. PubMed, Google Scholar, and PEDro databases were searched from inception until August 2020 with the keywords “urinary incontinence,” “pelvic floor disorders,” “lower urinary tract symptoms,” “overactive bladder,” and various terms for vitamin D. No language restrictions were imposed. The reference lists of all retrieved articles were also searched. Results: The search revealed 12 studies of different research methodologies after elimination. In 6 out of the 7 cross-sectional studies reviewed, a significant association between vitamin D deficiency or insufficiency and the onset and severity of UI was found. In 2 out of the 3 prospective studies included, no association between vitamin D intake and UI was found; however, both randomized controlled trials that were reviewed found that vitamin D supplementation is effective for the treatment of UI. Conclusions: The existing literature supports an association between low levels of serum vitamin D and UI. Initial evidence regarding the effect of vitamin D supplementation on UI is accumulating, yet additional, comprehensive research is warranted to establish these findings.