Phosphorus is found in the body both in organic and inorganic form, in bones and teeth (about 80%), but also in blood and soft tissues.
The main ingredients are milk and cheese, fish, meat, dried fruit and whole grains.
Absorption occurs as inorganic phosphate thanks to the intervention of vitamin D; factors that reduce it are: the presence of cations in the intestinal lumen that form insoluble salts, high pH and vitamin D deficiency with phosphates.
The elimination of phosphates takes place with the faeces, mainly in inorganic form (ie the non-absorbed fraction) and with urine.
Renal elimination is under the influence of the parathyroid hormone, which reduces its resorption.
The phosphorus requirement is comparable to that of calcium.
Functions in the body
Phosphorus has many functions in the body:
- as tricalcium phosphate and hydroxyapatite it is a constituent of the mineral fraction of bones and teeth;
- forms high-energy bonds, such as those present in ATP and phosphocreatine (chemical energy deposit forms);
- in the blood it constitutes an important buffer system for the regulation of the pH;
- it is a constituent of enzymes, proteins, phospholipids, nucleic acids and nucleotides;
- regulates important biochemical processes such as glucose uptake, phosphorylation mechanisms and the affinity of hemoglobin for oxygen;
- activates some vitamins.
Phosphorus deficiency
Cases of deficiency rarely occur, as phosphorus is present in most foods of animal and vegetable origin.
Phosphorus deficiencies are due to substances present in foods that hinder their absorption or the use of antacids and manifest themselves with weakness, demineralization of the bones, anorexia and malaise.
