Vitamin D and the kidney.

In the course of chronic kidney disease, alterations in vitamin D metabolism contribute to increases in the levels of parathyroid hormone and the development of skeletal disorders, and in addition, may contribute to hypertension, systemic inflammation and cardiovascular risk. In the course of chronic kidney disease, the production of 1,25-dihydroxyvitamin D from the kidney shows a progressive decline due to several factors, which include a reduction in the ability to convert 25-hydroxyvitamin-D to the active hormone, 1,25-dihydroxyvitamin D. The resulting 1,25-dihydroxyvitamin D, as well as 25-hydroxyvitamin D deficiency, correlates strongly with accelerated disease progression and mortality. An understanding of the pathophysiology involved leads to therapeutic strategies to correct these abnormalities, with the ultimate view to improve outcomes for patients with CKD.