Long-Term Treatment of Postmenopausal Osteoporosis with Active Vitamin D3, 1-Alpha-Hydroxycholecalciferol (1α-OHD3) and 1,24 Dihydroxycholecalciferol (1,24(OH)2D3)

Abstract

The effects of active vitamin D3 analogues on radial mineral content (RMC) in postmenopausal osteoporosis were examined. Seventy eight subjects with postmenopausal osteoporosis were divided into 5 groups; Group 1 (n=23) as the control group and Group 2 (n=27), Group 3 (n=8), Group 4 (n=9) and Group 5 (n=11) which were given 1 µg of 1,24(R) (OH)2D3 per day, 1 µg of 1, 24(S)(OH)2D3 per day, 0.5 and 1 µg of 1α-OHD3 per day for 6 to 24 months, respectively. After 3-months administration of these drugs, RMC values were significantly increased in Groups 2 (102.8±1.8%), 4 (103.9±3.3%) and 5 (114.2±3.6%), when compared with the controls (97.9±2.4%). RMC in Group 3 (97.9±2.4%) was not significantly different from the control value. The administration of 1α-OHD3 caused in increase in RMC in a dose-related manner. A rapid decrease in RMC was observed after withdrawal of the treatment in Groups 2, 4, and 5. A subsequent increase in RMC was observed after re-administration of 1α-OHD3 and 1,24(R)(OH)2D3. Serum Ca levels were increased in the group treated with 1, 24(R)(OH)2D3 and were decreased after the discontinuation of 1α-OHD3 administration. Serum Al-P activity was decreased by treatment with lα-OHD3 (1 µg per day) and a subsequent increase was observed in both groups treated with 1,24(R)(OH)2D3 and 1α-OHD3. Serum PTH levels were decreased by the administration of 1,24(R)(OH)2D3 and 1α-OHD3. In the group treated with 1 µg of 1α-OHD3 per day, hypercalcemia (2 out of 11 cases and these patients took calcium tablets) and an increase in BUN (1 out of 2 hypercalcemic patients) were observed. © 1985, The Japan Endocrine Society. All rights reserved.