Possible renoprotection by vitamin D in chronic renal disease: beyond mineral metabolism.

Vitamin D is typically viewed as a key player in the regulation of calcium and phosphate levels and the control of bone metabolism; however, growing evidence suggests that vitamin D deficiency may also have an important role in the progressive loss of renal function. Vitamin D deficiency is particularly frequent in patients with chronic kidney disease, in whom it is associated with increased mortality. Studies indicate that treatment with vitamin D analogues reduces proteinuria, suppresses the renin-angiotensin-aldosterone system (RAAS), and exerts anti-inflammatory and immunomodulatory effects. These pleiotropic effects render vitamin D a potentially interesting treatment modality for renoprotection in patients with chronic kidney disease. Whether vitamin D has clinically relevant renoprotective effects in addition to RAAS blockade is currently under investigation.