Effect of vitamin D on remaining kidney function after chronic kidney failure in preservation period patient

It is necessary to manage the secondary hyperparathyroidism at the early stage. We concern about vitamin D, one of the treatment for secondary hyperparathyroidism has some adverse effects on the kidney function. We administered oral vitamin D (alfa calcidol 0.25 microg/day) of 21 outpatients who have chronic renal failure of preservation period and observed clinical laboratory test result of serum creatinine, adjusted calcium, intact phosphate. Renal function is evaluated by the value of the decline of serum creatinine reciprocal. A small dosage of oral vitamin D may not effect on kidney function, but we should examine this though studying more cases.