Oral vitamin D supplements reduced the risk of hip and nonvertebral fractures in older people.

http://en.wikipedia.org/wiki/Pelvic_fracture

There are a couple precautions that may decrease the risk of getting a pelvic fracture. One study that examined the effectiveness of vitamin D supplementation found that oral vitamin D supplements reduced the risk of hip and nonvertebral fractures in older people. Certain types of equipment may help prevent pelvic fractures for the most at-risk groups.