Administration of calcium carbonate with adequate doses of vitamin D metabolite to patients on hemodialysis improves mild secondary hyperparathyroidism.

The effects of CaCO3 with vitamin D metabolite and without vitamin D metabolite on secondary hyperparathyroidism were investigated in 18 patients undergoing maintenance hemodialysis. 9 patients (Group 1) were treated with 1 microgram/day 1 alpha (OH)D3 and 2 g/day Al(OH)3, and the other 9 patients (Group 2) received 2 g/day Al(OH)3 without vitamin D metabolite. CaCO3 at amounts of 3 g/day was subsequently administered to all patients instead of Al(OH)3. The levels of mid portion-parathyroid hormone (M-PTH) in Group 2 and of 1,25-dihydroxyvitamin D3 in Group 1 during the baseline period were significantly increased as compared to those in the other group, respectively. In Group 1 only, the level of serum ionized calcium was appreciably elevated at the 4th and 12th weeks as compared to the baseline value, and the level of M-PTH was significantly decreased at the 4th and 12th weeks as compared to the baseline value. The levels of serum phosphate, calcitonin, magnesium and bicarbonate in both groups at the 4th and 12th weeks were not appreciably different from the baseline values. The level of serum aluminum in all patients of both groups were reduced at the 12th week as compared to the baseline values. A close correlation was recognized between M-PTH and the level of intact parathyroid hormone. It is concluded that prescription of 3g/day CaCO3, together with adequate doses of vitamin D metabolite, can ameliorate mild secondary hyperparathyroidism.