Serum 25-hydroxyvitamin D3 (25-OHD) concentrations are the recognized functional status indicator for vitamin D. Although there is no clear consensus, vitamin D 'insufficiency' has been considered in the range of 25- 75/80 nmol/L. Patients with acute hip fracture are at high risk for a recurrent hip fracture or other fragility fractures (and falls) and are a group who should be targeted for osteop