PURPOSE OF REVIEW: Vitamin D deficiency has been linked with impaired glucose metabolism, an established risk factor for cardiovascular disease. Effects of vitamin D may be particularly important in chronic kidney disease, because vitamin D metabolism is substantially impaired in this setting. The present review examines the potential role of vitamin D in improving glucose metabolism and clinical health outcomes in chronic kidney disease. RECENT FINDINGS: Impaired glucose metabolism is common in chronic kidney disease. Short-term studies on maintenance hemodialysis patients have shown that vitamin D treatment improves insulin secretion and sensitivity. Intervention studies on people without end-stage renal disease have yielded mixed results. Mounting evidence from observational studies links vitamin D treatment with decreased mortality. SUMMARY: Vitamin D therapy holds promise for improving health outcomes in chronic kidney disease. Improved glucose metabolism is one potential mechanism through which vitamin D may exert beneficial effects. However, further data from clinical trials are needed to test whether vitamin D has clinically relevant long-term effects on glucose metabolism and overall clinical outcomes.