Background: Several formulations of vitamin D and alendronate are available for the treatment of osteoporosis. The objective of this study was to examine efficacy and safety of calcifediol (25(OH)D) compared to cholecalciferol (vitamin D3) and also the relationship between different formulations of alendronate and adverse reactions.
Methods: We observed a population of women diagnosed with postmenopausal osteoporosis or osteopenia treated with alendronate 70 mg weekly associated to vitamin D3 or 25(OH)D at monthly total dose of 625 µg. Data collected both at baseline (T0) and at follow-up after at least 12 months of therapy (T1) were: demographic characteristics, BMI, full medical history, lumbar T-score, femur T-score, calcium, osteocalcin, alkaline phosphatase, PTH and vitamin D blood level.
Results: A total of 362 patients were enrolled in the study. Alendronate 70 mg + calcifediol (A+25(OH)D) group consisted of 202 patients while 160 patients were treated with alendronate 70 mg + cholecalciferol (A+D3). In the A+25(OH)D group, we observed a significant increase in lumbar T-score value (0.26±0.35 vs. 0.13±0.3) and serum vitamin D (20.64±20.71 vs. 6.07±7.61 ng/mL) levels compared to the A+D3 group (P<0.05). The lowest incidence of gastrointestinal adverse reactions was observed among patients taking alendronate 70 mg in drinkable solution form (P<0.05).
Conclusions: Alendronate 70 mg with calcifediol gives a better outcome in the treatment of osteoporosis according to lumbar T-score and vitamin D serum level observed at one-year follow-up compared to alendronate 70 mg with cholecalciferol. Both vitamin D formulations did not show to cause hypercalcemia in this study. Alendronate 70 mg in drinkable solution form is also associated with lowest incidence of gastrointestinal adverse reactions.