Comment on: ‘Vitamin D supplements and cancer incidence and mortality: a meta-analysis'
Results: Over 2–7 years of duration, vitamin D supplementations had little effect on total cancer incidence (400–1100 IU per day, summary relative risk (RR)1⁄4 1.00, 95% confidence interval (CI)1⁄4 0.94–1.06, I1⁄4 0%; four RCTs with combined 4333 cases), but significantly reduced total cancer mortality (400–833 IU per day, summary RR1⁄4 0.88, 95% CI1⁄4 0.78–0.98, I1⁄4 0%, three RCTs with combined 1190 deaths).