In this large meta-analysis of 12 double-blind randomized controlled trials (RCTs) for non-vertebral fractures and 8 randomized controlled trials for hip fractures, it was found that 400+ IU/day of Vitamin D resulted in a 29% decrease in non-vertebral bone fractures for the aged 65+ subgroup not living in an institution. There was an overall 20% decrease for non-vertebral fractures in all subgroups and a 18% decrease in hip fractures.
The study authors concluded:
“Nonvertebral fracture prevention with vitamin D is dose dependent, and a higher dose should reduce fractures by at least 20% for individuals aged 65 years or older.”