Epidemiology of calcium and vitamin D in bone loss.

Questions remain about the role of diet and skeletal bone loss. There is some indication from studies in premenopausal women that increased dietary calcium intake may be influential in promoting greater peak bone mass, although the evidence is inconsistent. A number of these studies have been reviewed recently. The findings from the clinical trials suggest that calcium supplementation as an effective intervention agent for bone loss in postmenopausal women must be more carefully investigated to identify at-risk women who will benefit from supplementation. The baseline levels of calcium intake and years since menopause should be considered. There is potential for a mild-to-moderate vitamin D deficiency leading to occult osteomalacia that contribute significantly to the excess bone loss and fracture observed in Caucasian women: The effects of diet, specific nutrients and metabolic bone disease may be difficult to ascertain when either the nutrient exposure is not well characterized or when the disease outcome is not well characterized. Additional work is needed to describe the relative influence of nutrient intake at different stages of the life cycle, the interactive nature between nutrients as they are expressed in bone metabolism and the role of nutrients according to level of hormones and exercise.