Vitamin D, Calcium & Mineral Metabolism, Extraskeletal Effects of Vitamin D and The Use of Nutritional Vitamin D in Chronic Kidney Disease

Vitamin D is a liposoluble prohormon and and a secosteroid that is produced in the skin after exposure to sunlight. It is turned to calcitriol that has an important role in the calcium and phosphate metabolism by different metabolic pathways. Vitamin D receptors excluding kidney tissues are available in the following organs and tissues; T lenfosit, brain, prostate, pancreas, gonad, breast tissues, muscles and colon. It is known that function of Vitamin D is not only to maintain healthy bones through arranging calcium homeostasis but also has pro-apopitotic, anti-inflammatory and immune modulator characteristics. In recent epidemiologic studies, low level vitamin D increases cancer incidence and cardiovascular mortality, and comes along with diabetes mellitus,  auto-immune diseases such as multiple skleroz. The development of Chronic Kidney Dissease (CKD) is  accompained by a progressive reduce in ability to produce 1,25-dihydroxyvitamin D. Low 25-hydroxyvitamin D levels are common in patients with all stages of CKD and this stuation has been triggered secondary hyperparathyroidism in CKD patients. Extrarenal conversion of 25-hydroxyvitamin D to 1,5-dihydroxyvitamin D may have significant biological role beyond those traditionally ascribed to vitamin D. In this review, we check outed vitamin D, calcium-mineral metabolism, the extrarenal effect of vitamin D, and nutritional vitamin D replacement in CKD.