Vitamin D did not prevent a single kind of fracture
In 25,871 adults over five years, 2,000 international units of vitamin D3 daily did not reduce total, non-spine or hip fractures, nor in any subgroup.
What the study found
The largest fracture trial found no benefit in any subgroup
The largest vitamin D fracture trial, in midlife and older adults not chosen for weak bones: 25,871 people, 1,991 fractures, five years of 2,000 international units of vitamin D3 a day, and no fall in total, non-spine or hip fractures, in any subgroup, even the lowest starting levels.
The caveat · No one recruited for weak bones
Nobody was recruited for having low vitamin D, low bone mass or osteoporosis, which is exactly the group the supplement is normally prescribed to. Fractures were reported by participants once a year and then checked against medical records. Hip fractures were few enough that their estimate spans a 30 percent reduction to a 47 percent increase.