The basis of 'nutritional' interventions for the prevention of postmenopausal osteoporosis and osteoporotic fracture is a large topic with much genetic and biochemical evidence, as well as the results of randomized controlled trials, to guide the investigator and clinician. The efficacy of treatment with calcium and vitamin D was once controversial, but with the advent of controlled clinical trials using bone mineral density as an endpoint it has become clear that calcium with or without vitamin D therapy can lead to reductions in the rate of bone loss in postmenopausal women of all ages. Furthermore, with certain caveats, calcium with vitamin D therapy in the older postmenopausal woman can lead to useful reductions in fracture rates and falls, especially in populations with reduced exposure to sunlight, which is potentially the majority of postmenopausal women in both developed and developing countries. However, estrogen, selective estrogen receptor modulators (SERMs) and bisphosphonates (especially when given in combination with calcium and vitamin D) are more efficacious in preventing fracture, particularly in postmenopausal patients with impaired bone structure.