Role of Vitamin D and Its Analogues in Diabetic Nephropathy: A Meta-analysis

Background: Diabetic nephropathy remains one of the most common causes of chronic kidney disease in the United States and is associated with significant morbidity and mortality. Recently, there have been emerging data highlighting the role of vitamin D and its analogue in chronic kidney disease especially diabetic nephropathy independent of its effect on bone metabolism. Methods: This study aimed to evaluate effect of supplementing vitamin D and its analogues on halting or slowing progression of diabetic nephropathy. Electronic databases (PubMed, Scopus, Google scholar) were searched and randomized controlled trials (RCTs) that investigated the use of vitamin D and its analogs for diabetic nephropathy were studied. This meta-analysis of RCTs performed in accordance with Preferred Reporting Items for Systematic review and Meta-analysis statement. Results: This meta-analysis included 9 RCTs and suggested a favorable trend with respect to an effect of vitamin D and its analogues on albuminuria though this did not reach statistical significance (MD, -0.17; 95% CI, - 0.34-0.01; P = 0.06]. Serum calcium was unaffected suggesting safe use of these agents. Conclusions: Use of vitamin D and its analogues may have potential as an adjuvant therapy for reducing albuminuria and slowing progression of diabetic nephropathy but further studies are needed.