Vitamin d, and kidney disease.

Mineral metabolism abnormalities, such as low 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and elevated parathyroid hormone (PTH), are common at even higher glomerular filtration rate than previously described. Levels of 25-hydroxyvitamin D (25(OH)D) show an inverse correlation with those of intact PTH and phosphorus. Studies of the general population found much higher all-cause and cardiovascular (CV) mortality for patients with lower levels of vitamin D; this finding suggests that low 25(OH)D level is a risk factor and predictive of CV events in patients without chronic kidney disease (CKD). 25(OH)D/1,25(OH)2D becomes deficient with progression of CKD. Additionally, studies of dialysis patients have found an association of vitamin D deficiency with increased mortality. Restoration of the physiology of vitamin D receptor activation should be essential therapy for CKD patients.