Therapy of osteoporosis: calcium, vitamin D, and exercise

Calcium supplementation has long been regarded as a fundamental part of the prevention and treatment of postmenopausal osteoporosis, but it is only in recent years that clear evidence has emerged demonstrating its impact on bone mass. Calcium supplementation does not completely arrest postmenopausal bone loss but slows the rate of decline by 30 to 50%. The effect of calcium supplementation on fracture incidence in postmenopausal women has not been established. Vitamin D deficiency is common in the frail elderly, particularly in countries where fortification or food with this vitamin is not practiced. Treatment of vitamin D deficiency has been associated with significant reductions in the number of hip fractures. The role of the potent vitamin D metabolites, calcitriol and alphacalcidol, in the management of postmenopausal osteoporosis is not clear. Although some studies show substantial benefits in bone density or fracture rate from the use of these compounds, the published data are inconsistent. In general, hormone replacement therapy and the potent bisphosphonates produce greater effects on bone density and there is a greater consistency among the results of the published studies of these other interventions. Controlled trials of exercise interventions in postmenopausal women show that exercise can positively influence bone density by a few percent. Exercise interventions in the elderly have been reported to decrease fall frequency by 10%. This latter effect may have a greater impact on fracture frequency than the modest benefits of exercise on bone-density.