[Vitamin D metabolism and chronic kidney disease].

Vitamin D is finally converted into the active form in the kidney, which is regulated and affected by several factors such as calcium . phosphate balance, parathyroid hormone (PTH), calcitonin and fibroblast growth factor 23 (FGF23). Activated vitamin D works as hormone and engages in calcium . bone metabolism. In chronic kidney disease, the active form can be decreased and therefore, renal osteodystrophy can be lead as consequences of mineral metabolism abnormality and unregulated PTH production/secretion as increased activity of the parathyroid glands (2HPT). Moreover, because chronic kidney disease (CKD)-associated abnormal states in above are detrimental to CKD patients not only in terms of renal osteodystrophy, but progress of cardiovascular disease and mortality. Therefore new concept is proposed as chronic kidney disease-mineral bone disorder (CKD-MBD).