Vitamin D and pelvic floor disorders in women: results from the National Health and Nutrition Examination Survey.

OBJECTIVE To estimate the prevalence of vitamin D deficiency in women with pelvic floor disorders and to evaluate possible associations between vitamin D levels and pelvic floor disorders. METHODS Using 2005-2006 National Health and Nutrition Examination Survey data, we performed a cross-sectional analysis of nonpregnant women older than 20 years of age with data on both pelvic floor disorders and vitamin D measurements (n=1,881). Vitamin D levels lower than 30 ng/mL were considered insufficient. The prevalence of demographic factors, pelvic floor disorders, and vitamin D levels were determined, accounting for the multi-stage sampling design; odds ratios (OR) and 95% confidence intervals (CI) were calculated to evaluate associations between vitamin D levels and pelvic floor disorders with control for known risk factors. RESULTS One or more pelvic floor disorders were reported by 23% of women. Mean vitamin D levels were significantly lower for women reporting at least one pelvic floor disorder and for those with urinary incontinence, irrespective of age. In adjusted logistic regression models, we observed significantly decreased risks of one or more pelvic floor disorders with increasing vitamin D levels in all women aged 20 or older (OR, 0.94; 95% CI, 0.88-0.99) and in the subset of women 50 years and older (OR, 0.92; 95% CI, 0.85-0.99). Additionally, the likelihood of urinary incontinence was significantly reduced in women 50 and older with vitamin D levels 30 ng/mL or higher (OR, 0.55; 95% CI, 0.34-0.91). CONCLUSION Higher vitamin D levels are associated with a decreased risk of pelvic floor disorders in women. LEVEL OF EVIDENCE III.