Vitamin D receptor activation: clinical outcomes.

Vitamin D has been recognized for years as a key player in the control of bone metabolism through the regulation of calcium and phosphate homeostasis. Vitamin D deficiency appears to be common in the general population as a result of decreased dietary intake, diminished absorption, or limited exposure to sunlight. Vitamin D deficiency results in increased circulating levels of parathyroid hormone, which has several disadvantageous effects on bone metabolism. The intake of ordinary doses of vitamin D supplements appears to be associated with a decrease in total mortality rates. In the chronic kidney disease (CKD) population, vitamin D receptor (VDR) activation deficiency is even more severe than in a non-CKD population, with a 25-(OH) vitamin D level being an independent predictor of all-cause mortality. Similarly to nonrenal populations, the corrections of vitamin D deficiency/treatment with vitamin D is associated with better survival. Selective VDR activators appears to be better than calcitriol in terms of survival or adverse effects.