Zhang Y, et al. - Whether serum 25-hydroxyvitamin (25[OH]D) levels have an impact on all-cause and cardiovascular mortality in dialysis patients was examined via a systematic review and meta-analysis of clinical studies including patients receiving maintenance dialysis identified via a systematic literature search in PubMed and Embase. The search was last updated on February 10, 2017. The evidence from 18 moderate to high-quality cohort studies (with an overall sample of 14,154 patients on dialysis) was analyzed. Findings revealed a significant link between increased serum 25(OH)D level and both lower all-cause mortality and lower cardiovascular mortality in dialysis patients. Despite marked heterogeneity, 0.78 was the estimated relative risk of all-cause mortality per 10 ng/mL increase in serum 25(OH)D level. Per 10 ng/mL increase in serum 25(OH)D level, the estimated relative risk of cardiovascular mortality was 0.71, with substantial heterogeneity.