[Levels of dihydroxyvitamin D3 and hydroxyvitamin D in patients with chronic renal insufficiency].

According to the aim of our research to find a regulatory of changes of the serum levels of 1.25 dihydroxyvitamin D3 and 25 OH D vitamin, we examined their serum concentration in 43 among 100 pts. with normal and impaired renal function with different stages of chronic renal failure (CRF). In all of 100 pts. we measured plasma phosphate and calcium concentration and endogenous creatinine clearance. The results of our research showed homeostasis abnormalities in all of parameters we examined. We found out that the serum 1.25 (OH)2 D3 levels decreased in early course of CRF, hypovitaminosis occurred when glomerular filtration rate reaches values equal or less than 50.7 ml/min. Hypovitaminosis of 25 OH D expressed in end-stage of CRF, while hyperphosphatemia was commonly seen in moderate CRF, when GFR became less than 28.6 ml/min. Hypocalcemia obtained when GFR was equal or less than 47.7 ml/min.