Preventing Osteoporosis Using Denosumab

Inclusion Criteria: Ambulatory male and female residents with osteoporosis or low bone mass (at risk for fracture) ages 65 and older will be considered if: * Reside in long-term care institution (nursing home or assisted living facility); and * HaveOsteoporosis: (1) by bone density \[spine, hip or forearm Bone Mineral Density (BMD) T-score ≤ -2.5\]; (2) A previous adult fragility fracture of the spine or hip; or (3) Would be treated based on FRAX® and the National Osteoporosis Foundation (NOF) treatment thresholds of a 10 year risk of ≥ 20% for a major fracture or ≥ 3% for hip fracture suing femoral neck BMD. Exclusion Criteria: * Institutionalized residents with subacute illnesses who are not expected to survive or who will be discharged in \< 2 years. * Non-ambulatory residents (those who cannot stand and pivot with assistance in order to transfer to the DXA table). * Those currently on therapy (including bisphosphonate, denosumab, or teriparatide) or who have been on a bisphosphonate for \> 1year during the previous 2 years because some bisphosphonates are long acting. * Those with a history of hypocalcemia or contraindication for treatment. We will screen for these conditions by detailed history, chart review, and baseline laboratory analyses. * Those with vitamin D levels \< 25ng/mL will be treated with vitamin D 50,000 IU/wk for 8 weeks; they will be enrolled if the follow-up vitamin D level is 25 ng/mL or more (if after 2 rounds of vitamin D repletion their vitamin D level is not at least 25 ng/mL, they will not be eligible to be randomized into the study). * Those on dialysis or with stage 5 chronic kidney disease (eGFR\<15ml/min) will be excluded at screening. * Those requiring tooth extraction or oral surgery will not be enrolled until cleared by a dentist. * Patients will be allowed to continue on glucocorticoids and anticonvulsants because their use is common in this population. * Those on glucocorticoids and anticonvulsants will be allowed to continue in the study because their use is common in this population. * Those on hormone replacement therapy (HRT), raloxifene, or prescribed protective hip pads by their Primary Care Physician (PCP) will be allowed to participate and continue on these therapies. * We will suggest that participants stop long-term calcitonin as it has been discontinued in Europe due to cancer concerns.