The aim of this study is to compare a low versus high intensity physiotherapy early rehabilitation program combined with a low versus high dose vitamin D early rehabilitation program in a randomized controlled trial among elderly patients with acute hip fracture in an acute care setting. The primary outcome to be compared between treatment arms is the rate of falls during a 12-month follow-up. Secondary outcomes are injurious falls, number of persons who fell, low-trauma fractures (at the hip, forearm, humerus, pelvis, ankle, spine, femur, tibia), disability, quality of life (Euro-Qol), mortality and health care utilization. Another secondary outcome will be admission to nursing home compared between treatment arms among subjects, who are community-dwelling prior to the index hip fracture. Admission to nursing home is the marker of loss of independence for the individual, but also triggers high cost for the society.