ELEVATED PTH LEVELS IN HYPOVITAMINOSIS-D ARE MORE RAPIDLY SUPPRESSED BY THE ADMINISTRATION OF 1,25-DIHYDROXY-VITAMIN-D-3 THAN BY VITAMIN-D-3

Objective: To assess markers of bone metabolism in two groups of inpat ients with hypovitaminosis D and elevated PTH levels receiving two dif ferent vitamin D medications. Methods: 26 patients with secondary hype rparathyroidism (2 degrees HP) were treated either with 800 IU choleca lciferol and 1000 mg calcium or 0.5 mu g calcitriol plus 500 mg calciu m daily for 6 months, 25-OH-vitamin D-3, 1,25-dihydroxy-vitamin D-3, i ntact PTH, calcium and urinary N-telopeptides of bone collagen I were measured at baseline, 3 and 6 months. Results: PTH levels decreased ea rlier in the calcitriol group than in the cholecalciferol group. After six month no difference could be documented Lowering of urinary N-tel opeptides excretion was observed in both groups. Conclusion: The use o f both forms of vitamin D supplementation appears to be useful for pat ients with hypovitaminosis D, elevated PTH levels and high telopeptide excretion.