[An importance of vitamin D metabolites assessment in patients with impaired renal function]

The goal of this prospective multicentric study was to assess concentrations of vitamin D metabolites in patients with renal insufficiency and to monitor response of calcium phosphate metabolism parameters to a focused individualised therapy. The sample consisted of 184 patients, 66 of them were undergoing regular dialysis (Ccreat 0.11 +/- 0.05 ml/sec., age 57.6 +/- 16.6) and 118 patients were dispensed for renal insufficiency (Ccreat 0.42 +/- 0.23 ml/sec., age 60.8 +/- 11.0). After an assessment of basic parameters of bone metabolism (Ca, Pi, ALP) and parameters of acidobasic balance, calcidiol, calcitriol, and parathormon were assessed by radiation immunisation and than the used treatment was evaluated and adjusted according to results of the assessment. Two month later laboratory tests were done. Entry concentrations of calcidiol were in 73% of patients in reference area. However, according to clinical recommendations the bottom value of the reference area had to be reevaluated towards higher values. Such more strict criteria suited only 20% of patients. Calcitriol levels in reference area were found in 30% of patients, after treatment adjustment in 49% of patients. Treatment with vitamin D pharmaceuticals was often limited by hyperphosphataemia, low PTH or hypercalinemia. Input levels of calcitriol in nondialised patients significantly correlated with input calcidiol, 1alpha-hydroxylasis in kidneys could be stimulated in them via calcidiol administration. Attention deserve especially low calcidiol and calcitriol levels in patients with renal failure because timely, individualised and controllable supplementation of vitamin D metabolites in renal insufficiency serves as a prevention of later advanced forms of bone metabolism impairment in a period of dialysis treatment.