Comparison of the effects of cholecalciferol and calcitriol on calcium metabolism and bone turnover in Chinese postmenopausal women with vitamin D insufficiency.

ABSTRACT

AIM: To compare the effects of cholecalciferol (800 IU/d) and calcitriol (0.25 µg/d) on calcium metabolism and bone turnover in Chinese postmenopausal women with vitamin D insufficiency. METHODS: One hundred Chinese postmenopausal women aged 63.8±7.0 years and with serum 25-hydroxyvitamin D [25(OH)D] concentration <30 ng/mL were recruited. The subjects were divided into 2 groups based on the age and serum 25(OH)D concentration 50 subjects (group A) received cholecalciferol (800 IU/d), and 50 subjects (group B) received calcitriol (0.25 µg/d) for 3 months. In addition, all the subjects received Caltrate D (calcium plus 125 IU cholecalciferol) daily in the form of one pill. The markers of calcium metabolism and bone turnover, including the serum levels of calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone, 25(OH)D and ß-CrossLaps of type I collagen containing cross-linked C-telopeptide (ß-CTX), were measured before and after the intervention. RESULTS: After the 3-month intervention, the serum 25(OH)D concentration in group A was significantly increased from 16.01 ± 5.0 to 20.02 ± 4.5 ng/mL, while that in group B had no significant change. The serum calcium levels in both the groups were significantly increased (group A from 2.36 ± 0.1 to 2.45 ± 0.1 mmol/L; group B from 2.36 ± 0.1 to 2.44 ± 0.1 mmol/L). The levels of serum intact parathyroid hormone in both the groups were significantly decreased (group A from 48.56 ± 12.8 to 39.59 ± 12.6 pg/mL; group B from 53.67 ± 20.0 to 40.32 ± 15.4 pg/mL). The serum levels of ß-CTX in both the groups were also significantly decreased (group A from 373.93 ± 135.3 to 325.04 ± 149.0 ng/L; group B from 431.00 ± 137.1 to 371.74 ± 185.0 ng/L). CONCLUSION: We concluded that both cholecalciferol (800 IU/d) and calcitriol (0.25 µg/d) plus Caltrate D modifies the serum calcium and bone turnover markers in Chinese postmenopausal women with vitamin D insufficiency. In addition, cholecalciferol (800 IU/d) significantly increased the serum 25(OH)D concentration.