Phosphorus

Phosphorus, as phosphate, is essential for all life and is widely distributed in both plant and animal foods. A diet adequate in other nutrients, particularly calcium and protein, will automatically be adequate in phosphorus. ECF [Pi], which varies little with dietary phosphorus intake, is itself vital for normal physiological function in all the higher vertebrates, and the principal abnormalities of phosphate metabolism involve either excessively low or excessively high concentrations of this critical anion. ECF [Pi] is regulated by a feedback control loop in which fibroblast growth factor -23 (FGF -23) is the effector hormone. Low serum phosphorus is most commonly due to increased renal phosphorus clearance produced by high levels of parathyroid hormone or FGF -23. The result is rickets or osteomalacia as well as muscle weakness and general metabolic dysfunction of all body tissues and organs. High serum phosphorus is most commonly due to decreased renal clearance as a result of kidney failure. The results include extra -osseous calcification, especially of critical arterial systems.