The Roles of Calcium and Vitamin D in the Prevention of Osteoporosis

Calcium supplementation produces small beneficial effects on bone mass throughout postmenopausal life and may reduce fracture rates by more than this change would predict--possibly by as much as 50%. There is little reason to use vitamin D in young populations that are replete in this compound, but in the elderly at risk of vitamin D deficiency, there is now evidence of significant reductions in nonvertebral fracture rates from physiologic replacement regimens. Some of the most substantial reductions in fracture rates have been found with combined therapy with calcium and vitamin D, and in these protocols it is not clear which is the principal active agent or whether, in fact, the combination is necessary for optimal antifracture efficacy.