An adult human body contains about 400-700mg of phosphorus. About eighty per cent of the body’s phosphorus is deposited in the bones and teeth as calcium phosphate.
The metabolism of food used by the body requires compounds containing phosphorus. The human gets this phosphorus through foods eaten. These include egg, beans, peas and milk.
The majority of dietary phosphorus is in the form of free phosphate. Absorption of phosphorus occurs throughout the length of the small intestine but primarily in the duodenum and jejunum.
About 50% to 70% of dietary phosphorus is absorbed, which absorption from animal products at the upper end of the range, and that from phytic acid-containing foods at the lower end. The active vitamin D hormone calcitriol helps absorption of phosphorus.
The most favorable absorption of inorganic phosphate takes place when calcium and phosphorus are ingested in approximately equal amount. Because milk has calcium and phosphorus in equal amounts, it is a good source of phosphorus.
About 70% of the phosphate in the blood circulates as part of phospholipids, primarily in lipoprotein, cells and platelets. The remaining 30% is largely dissolved inorganic phosphates.
Phosphorus in the body is regulated by its excretion by the kidneys. Source of 60-90% of the urinary phosphate excretion is dietary.
Dietary phosphorus
