Vitamin D and chronic kidney disease

Abstract

Chronic kidney disease (CKD) has been recognized as a significant global health problem because of the increased risk of total and cardiovascular morbidity and mortality. Vitamin D deficiency or insufficiency is common in patients with CKD, and serum levels of vitamin D appear to have an inverse correlation with kidney function. Growing evidence has indicated that vitamin D deficiency may contribute to deteriorating renal function, as well as increased morbidity and mortality in patients with CKD. Recent studies have suggested that treatment with active vitamin D or its analogues can ameliorate renal injury by reducing fibrosis, apoptosis, and inflammation in animal models; this treatment also decreases proteinuria and mortality in patients with CKD. These renoprotective effects of vitamin D treatment are far beyond its classical role in the maintenance of bone and mineral metabolism, in addition to its pleiotropic effects on extramineral metabolism. In this review, we discuss the altered metabolism of vitamin D in kidney disease, and the potential renoprotective mechanisms of vitamin D in experimental and clinical studies. In addition, issues regarding the effects of vitamin D treatment on clinical outcomes are discussed. © 2014 The Korean Association of Internal Medicine.