To ensure aging Veterans remain active and mobile with as little musculoskeletal pain as possible, new approaches to the prevention of osteoporosis and promotion of timely bone regeneration following a fracture are necessary. This collaborative research study brings together a group of VA investigators with diverse perspectives, insights, models, and techniques, to synergistically attack a major clinical problem that leads to high morbidity and mortality among Veterans, a bone fracture. The overall research strategy of each integrated project is to use pre-clinical models of a disease that either weakens bone or delays bone repair, to investigate novel ways to enhance the ability of parathyroid hormone (PTH) to promote bone formation, and to assess disease and treatment effects on bone in a unified, stringent manner. Already under-diagnosed and under- treated, osteoporosis is likely to increase the number of fragility fractures being treated at VA hospitals without novel tools for early detection and novel treatment strategies that circumvent the rare but devastating side effects of current therapies that inhibit bone loss. Addressing this unmet clinical need, the overall aims are to identify therapeutic strategies to improve bone health among Veterans and to enhance the bone anabolism of PTH signaling. The collaboration will address this overarching hypothesis: health problems disproportionately affecting Veterans activate signaling pathways that increase bone resorption, suppress bone formation, or impede the transition of cartilage to bone in a fracture callus such that improvements in the clinical management of osteoporosis lie in understanding how these health problems hurt bone health.