Phosphorus nutrition and the treatment of osteoporosis.

Bone mineral consists of calcium phosphate, and phosphorus is as important as calcium in supporting bone augmentation and maintenance. Although typical adult diets contain abundant phosphorus, 10% to 15% of older women have intakes of less than 70% of the recommended daily allowance. When these women take high-dose calcium supplements that consist of the carbonate or citrate salts, all their food phosphorus may be bound and hence unavailable for absorption. Current-generation anabolic agents for treating osteoporosis require positive phosphorus balances of up to 90 mg/d. Attention to the nutritional adequacy of the diets of such patients is essential if they are to realize the full potential of such therapies. A calcium phosphate supplement may be preferable to the usual carbonate or citrate salts because its phosphate serves to spare food phosphorus.