Importance of Dietary Phosphorus for Bone Metabolism and Healthy Aging

Inorganic phosphate (P(i)) plays a critical function in many tissues of the body: for example, as part of the hydroxyapatite in the skeleton and as a substrate for ATP synthesis. P(i) is the main source of dietary phosphorus. Reduced bioavailability of P(i) or excessive losses in the urine causes rickets and osteomalacia. While critical for health in normal amounts, dietary phosphorus is plentiful in the Western diet and is often added to foods as a preservative. This abundance of phosphorus may reduce longevity due to metabolic changes and tissue calcifications. In this review, we examine how dietary phosphorus is absorbed in the gut, current knowledge about P(i) sensing, and endocrine regulation of P(i) levels. Moreover, we also examine the roles of P(i) in different tissues, the consequences of low and high dietary phosphorus in these tissues, and the implications for healthy aging.