A Study to Evaluate Alendronate Sodium /Vitamin D3 Combination Tablets(FOSAMAX PLUS) Versus Calcitriol in the Treatment of Osteoporosis in Postmenopausal Women in China (MK-0217A-264)

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