To compare change in fractional calcium absorption following administration of MK0217A relative to matching placebo, in postmenopausal women with osteoporosis

Placebo will be administered over a 4 week, single-blind run-in phase. Calcium, as citrate-malate, will be administered throughout the study at an individualized dose supplementing the patient's daily dietary calcium intake to a total of approximately 1200 mg. At the end of the stabilization period, baseline calcium absorption will be determined and patients will be randomized to receive either MK0217A, or matching placebo once weekly for 4 weeks.

Inclusion Criteria:

• The patient is a postmenopausal osteoporotic female
• The patient is willing to limit direct sunlight exposure during the course of the study
• The patient must be ambulatory
• The patient has serum 25-hydroxyvitamin D =25 ng/mL

Exclusion Criteria:

• The patient is contraindicated to bisphosphonate therapy
• The patient has a vitamin D deficiency
• Patient will be excluded if their weight is above 85 kg
• The patient has a history of prior osteoporotic fracture
• The patient is currently or has received in the past treatment with effects on bone or calcium metabolism
• The patient has malabsorption syndrome
• The patient has active thyroid disease
• The patient has metabolic bone disease
• The patient had a myocardial infarction within 6 months of screening visit
• The patient has impaired renal function
• The patient is currently or has been a smoker in the last year