Purpose: Our goal was to evaluate vitamin D supplementation for preventing or treating overactive bladder and urinary incontinence in men. MATERIALS AND

Methods: Ancillary study of men aged ≥55 years in VITAL (VITamin D and OmegA-3 TriaL). Randomized treatments included: vitamin D(3) (cholecalciferol), marine omega-3 fatty acids, or matching placebo. Structured urinary incontinence questions measured the prevalence of overactive bladder at year 5 and urinary incontinence at years 2 and 5, along with incidence and progression of urinary incontinence from years 2 to 5. Prespecified subgroup analyses examined men with low baseline serum 25-hydroxyvitamin D (<20 ngml).

Results: Among the 11,486 men who provided data at year 2 and 10,474 at year 5, mean age was 68 years at year 2, with 23% racial/ethnic minorities. In primary analyses, vitamin D supplementation compared to placebo did not lower odds of overactive bladder at year 5 (OR 0.97, 95% CI 0.87-1.08) or weekly urinary incontinence at year 2 (OR 0.94, 95% CI 0.83-1.05) or year 5 (OR 0.98, 95% CI 0.88-1.09). We found interactions of baseline serum 25-hydroxyvitamin D level with vitamin D supplementation for overactive bladder (P value for interaction = .001), and secondarily, for any urinary incontinence at year 2 (P value for interaction = .05). Men with baseline 25-hydroxyvitamin D <20 ngml, who were assigned to vitamin d supplements, had lower odds of overactive bladder (or 0.51, 95% ci 0.35-0.76) compared placebo, yet higher any urinary incontinence 1.24, 0.93-1.64).

Conclusions: Overall, vitamin D supplementation did not improve overactive bladder or urinary incontinence compared to placebo. However, specific use of vitamin D in men with lower 25-hydroxyvitamin D levels had inconsistent findings.