This study will evaluate whether the once weekly administration of the combination tablet alendronate/vitamin D3 (FOSAMAX PLUS) will increase lumbar spine bone mineral density (BMD) more than the daily use of calcitriol.

This was a 6-month, randomized, open-label, active-comparator controlled, parallel-group study with a 6-month extension to evaluate the safety and efficacy of alendronate sodium 70 mg plus vitamin D3 5600 IU combination tablets versus calcitriol in the treatment of osteoporosis in postmenopausal women in China. Participants were randomly assigned to receive alendronate 70 mg plus vitamin D3 5600 IU combination tablet once weekly orally or calcitriol 0.25 μg daily orally.

Inclusion Criteria:

• Meets one of the following BMD criteria:
• Has BMD T-score ≤-2.5 in at least one of the anatomic sites including lumbar spine, total hip, and femoral neck, OR
• Has prior non-pathological fragility fracture (of spine, wrist, humerus or clavicle) and BMD T-score ≤-1.5 in at least one of the anatomic sites including lumbar spine, total hip, and femoral neck sites
• Must have a baseline 25-hydroxyvitamin D ≥8 ng/mL (20 nmol/L)
• Is ambulatory
• Has been postmenopausal for at least one year

Exclusion Criteria:

• Has any contraindication to alendronate, including abnormalities of the esophagus which delay esophageal emptying (such as stricture or achalasia), or inability to stand/sit upright for at least 30 minutes, or hypersensitivity to alendronate and vitamin D, or hypocalcemia
• Has any contraindications to calcitriol, and/or vitamin D, including hypercalcemia, hypercalciuria, or active kidney stone disease
• Had a prior hip fracture
• Has received treatment with any of the following: anabolic steroid agent within the past 12 months, systemic glucocorticoids for more than 2 weeks in the past 6 months, oral bisphosphonates more than 3 months within the past 2 years, any lifetime use of an intravenous administration of zoledronate, immunosuppressant other than methotrexate, fluoride treatment at a dose greater than 1 mg/day for more than 2 weeks within the past 3 months, strontium containing products for more than 2 weeks within the past 6 months, Parathyroid hormone for more than 2 weeks within the past 3 months, current use of chemotherapy, or heparin, growth hormone for more than 2 weeks within the past 6 months, active hormonal vitamin D analogs (e.g., alphacalcidol, calcitriol) in the past 30 days, or more than 5 days treatment of active hormonal vitamin D analogs between 30 and 60 days prior to study entry., use of vitamin A (excluding beta carotene) >10,000 IU daily, unless willing to discontinue this dose during the study, current use of, lithium, or anti-convulsants, current use of calcium supplement in amount excess of 1500 mg daily, unless willing to discontinue this dose during the study, estrogen with or without progestin within the prior 6 months, Raloxifene or other selective estrogen receptor modulator ([SERM] including tamoxifen), tibolone, or an aromatase inhibitor within the prior 6 months and/or sub-cutaneous calcitonin or intra-nasal calcitonin within the prior 6 months
• Has a history of malignancy within previous 5 years
• Has one or more of the following concomitant conditions: uncontrolled upper gastrointestinal disorders, myocardial infarction, unstable angina, stroke and revascularization condition within 3 months, malabsorption syndrome, uncontrolled primary or secondary hyperparathyroidism, uncontrolled thyroid disease, renal insufficiency, uncontrolled genitourinary, cardiovascular, hepatic, renal, endocrine, hematologic, neurological, psychiatric, or pulmonary diseases; unexplained laboratory test abnormality or other conditions, uncontrolled hypertension, new onset diabetes (within 3 months), poorly controlled hyperglycemia or abnormal fasting glucose, hypoglycemia for any cause, history of, or evidence for metabolic bone disease other than osteoporosis, abnormal serum calcium or phosphate, and/or active renal stone disease when a calcium supplement is contraindicated