Calcifediol (25-hydroxyvitamin D) improvement and calcium-phosphate metabolism of alendronate sodium/vitamin D3 combination in Chinese women with postmenopausal osteoporosis: a post hoc efficacy analysis and safety reappraisal

Abstract Background Vitamin D (VD) insufficiency or deficiency is a frequent comorbidity in Chinese women with postmenopausal osteoporosis (PMO). The present study aimed to investigate 25-hydroxyvitamin D [25(OH) D] improvement and calcium-phosphate metabolism in Chinese PMO patients treated with 70 mg of alendronate sodium and 5600 IU of vitamin D3 (ALN/D5600). Methods Chinese PMO women (n = 219) were treated with 12-month ALN/D5600 (n = 111) or calcitriol (n = 108). Changes in 25(OH) D at month 12 were post hoc analyzed by the baseline 25 (OH) D status using the longitudinal analysis. The main safety outcome measures included serum calcium and phosphate and 24-h urine calcium, and the repeated measures mixed model was used to assess the frequencies of the calcium-phosphate metabolic disorders. Results Absolute change in mean serum 25(OH) D level was the greatest in VD-deficient patients and least in VD-sufficient patients at months six and 12 (both, P