EFFECT OF ORAL CALCIUM ON NONINVASIVE INDEXES OF BONE-FORMATION AND BONE MASS IN HEMODIALYSIS-PATIENTS - A RANDOMIZED DOUBLE-BLIND PLACEBO-CONTROLLED STUDY

The purpose of this study was to evaluate the effect of high-dose oral calcium on biochemical indices of bone formation, bone bisphosphonate clearance (BBC) and bone mineral content (BMC) of the distal forearm in patients undergoing hemodialysis. Eighteen patients agreed to parti cipate and were randomized in a double-blind manner to receive either 2 g elemental calcium/day (n = 9) or placebo (n = 9) for 6 months. Pre vious treatment with aluminum-containing phosphate binders was continu ed unchanged throughout the study. In the placebo group, serum alkalin e phosphatase and osteocalcin tended to increase by 8.0 and 10.2%, res pectively, while BBC changed significantly by 49.5% (p < 0.05). In the calcium group the opposite was observed with small decreases in alakl ine phosphatase and osteocalcin by 8.2 and 11.0%, respectively, and no change in BBC. BMC decreased by 5.0% in the placebo group, but increa sed by 5.2% in the calcium group, resulting in a difference of 10.2% ( p < 0.05). The present study demonstrates that high-dose oral calcium tends to reduce bone turnover and seems able to prevent bone loss in h emodialyzed patients.