EFFECT OF ORAL CALCIDIOL TREATMENT ON ITS SERUM LEVELS AND PERITONEALLOSSES

Objectives: To evaluate calcidiol serum levels in a group of continuou s ambulatory peritoneal dialysis (CAPD) patients and the effect of ora l calcidiol treatment on serum levels and peritoneal losses. Study des ign: Twenty patients (13 female, 7 male) were studied for 12 - 60 mont hs. Their ages ranged 22 - 72 years (mean 46+/-15). Serum calcidiol, t otal protein and urea were determined at baseline and after the admini stration per os of 0.133 mcg/day of calcidiol for 10 days. At the same time, calcidiol and total protein were measured in peritoneal effluen t at baseline and at 5, 10, and 40 days after starting this treatment. Results: A significant and direct correlation between the calcidiol d ialysis/plasma ratio and the peritoneal protein losses was found, both before and 40 days after calcidiol administration when calcidiol seru m levels were the lowest. As calcidiol serum levels rose to the normal range in the course of the study, peritoneal losses of this metabolit e increased slightly and correlated with calcidiol serum levels and ur ea mass transfer coefficient (MTC); the significant correlation betwee n calcidiol serum levels and peritoneal protein losses disappeared. Co nclusions: When serum calcidiol levels are low, calcidiol peritoneal l osses in patients on CAPD correlate with protein peritoneal losses. Ho wever, when serum calcidiol levels rise, the calcidiol peritoneal loss es correlate with calcidiol serum levels and urea MTC, and not with pr otein peritoneal losses.