This study is designed as a single-blind RCT in 80 postmenopausal women to compare the effect of immediate administration of daily calcium supplementation (1000 mg calcium) or two daily dosages of calcium + vitamin D (1000 mg calcium + 880 IU vitamin D or 1000 mg calcium + 1760 IU vitamin D) to standard care (administration of vitamin D3 12 weeks after fracture) in terms of calculated bone strength based on analysis of cortical and trabecular bone parameters using HR-pQCT, fracture healing and functional outcome.

Inclusion Criteria:

• Postmenopausal women older than 50 years who present themselves in clinic with a distal radius fracture due to a trauma.
• Patients with a stable distal radius fracture treated by cast immobilization.
• Patients who understand the conditions of the study and are willing and able to comply with the scheduled biochemical and radiographic evaluations and the prescribed rehabilitation.
• Patients who signed the Ethics Committee approved specific Informed Consent Form prior to inclusion.

Exclusion Criteria:

• Patients who underwent surgery of the wrist or radius on a previous occasion on the same side or who need surgery this time.
• Patients with active or suspected infection such as pneumonia or complicated urinary tract infection in the last 3 months.
• Patients with malignancy or a pathological fracture in the last 12 months.
• Patients with a neuromuscular or neurosensory deficit, e.g. Parkinson's disease, which would limit the ability to assess the performance during the healing period.
• Patients with known systemic or metabolic disorders leading to progressive bone deterioration, such as: hyperthyroidism, hyperparathyroidism, chronic kidney disease with eGFR<30 ml/min, sarcoidosis, hypercalcemia,
• Patients with an active inflammatory disease during the last year such as rheumatoid arthritis, systemic lupus erythematous, inflammatory bowel disease, e.g. Crohn's disease and ulcerative colitis.
• The use of glucocorticoids during the last 12 months.
• Patients with an allergy to calcium, calcium carbonate, cholecalciferol, aspartame, citric-acid, lactose, dimethicone, methylcellulose, sorbic acid, macrogole, polyvidone, mannitol, orange flavour, natriumsaccharine, starch or sucrose.
• Patients, who as judged by the principal Investigator, are mentally incompetent or are unlikely to be compliant with the follow-up evaluation schedule.
• Patients with other severe concurrent joint involvements that can affect their outcome.
• Patients who are already selected for another trial concerning distal radius fractures.