ORAL CALCIUM EFFECTIVELY REDUCES PARATHYROID-HORMONE LEVELS IN HEMODIALYSIS-PATIENTS - A RANDOMIZED DOUBLE-BLIND PLACEBO-CONTROLLED STUDY

The objective of this study was to elucidate the effect of oral calciu m supplement upon the severity of secondary hyperparathyroidism and hy perphosphatemia in patients undergoing hemodialysis. Twenty-three acce pted to participate and were randomly allocated to receive in a double -blind manner either 2 g elemental calcium per day (n = 12) or placebo (n = 11) for 6 months. Three patients dropped out leaving 10 patients in each group. In the calcium group serum ionized calcium increased s ignificantly during the 1st month from 1.15+/-0.02 to 1.29+/-0.04 mmol /l (mean+/-SE) and was then stabilized at an average of 1.26+/-0.02 mm ol/l for the remaining 5 months. Serum intact parathyroid hormone (PTH ) decreased in average by 54% within the 1st month and remained at tha t level for the following months. Hyperphosphatemia remained stable th roughout. On the contrary, in the placebo group, serum concentrations of ionized calcium and intact PTH remained unchanged, while serum phos phate increased significantly. The present study demonstrates that ora l calcium reduces secondary hyperparathyroidism and prevents the progr ession of hyperphosphatemia in patients undergoing hemodialysis.