[Vitamin D and chronic kidney disease: increasing role for an old vitamin]

Patients with chronic kidney disease exhibit a high mortality risk that is not fully explained by the classical cardiovascular risk factors. Vitamin D deficiency highly prevalent among CKD patients is independently associated with an increased mortality risk in this population. Advances in the understanding of vitamin D physiology dramatically changed the view on the role of this vitamin in kidney disease. Extra-renal actions on a variety of tissues have been identified. By its cardiovascular effects for instance, correction of vitamin D insufficiency might help to reduce the excess of mortality among patients with chronic kidney disease. This article summarizes the sum of knowledge on the roles of vitamin D in kidney disease. Recommendations on screening and substitution with vitamin D in this high-risk population are then proposed.