Improved patient outcomes in chronic kidney disease: optimizing vitamin D therapy.

Secondary hyperparathyroidism is an early complication of chronic kidney disease (CKD). Vitamin D deficiency and reduced synthesis of 1,25-dihydroxyvitamin D (calcitriol) early in the progression of CKD leads to abnormal mineral metabolism. Vitamin D deficiency leads to increased parathyroid hormone and remodeling of bone that releases calcium and phosphorus, resulting in vascular calcification. Vitamin D deficiency is associated with cardiovascular disease and contributes to the high morbidity and mortality in patients with CKD.