Vitamin D in chronic kidney disease.

Vitamin D deficiency is highly prevalent in patients with chronic kidney disease (CKD). The low vitamin D status is, to a large extent, caused by dysregulation of vitamin D metabolism as a result of renal insufficiency. Recent studies indicate that vitamin D-deficiency may promote or accelerate the progression of CKD, whereas treatment with low calcemic vitamin D analogs can reduce proteinuria and ameliorate renal damage in animal models of kidney disease and in patients with CKD. The renoprotective activity of vitamin D regulates multiple signaling pathways known to play important roles in renal injury. These findings underscore the importance of correcting vitamin D deficiency with vitamin D supplementation or with activated vitamin D analogs in the management of CKD.