Definition

Phosphorus is a mineral that makes up 1% of the total body weight. It is present in every cell of the body, but 85% of the body's phosphorus is found in the bones and teeth.

Alternative Names

Diet - phosphorus

Function

The main function of phosphorus is in the formation of bones and teeth. It plays an important role in the body's utilization of carbohydrates and fats and in the synthesis of protein for the growth, maintenance, and repair of cells and tissues. It is also crucial for the production of ATP, a molecule the body uses to store energy.

Phosphorus works with the B vitamins. It also assists in the contraction of muscles, in the functioning of kidneys, in maintaining the regularity of the heartbeat, and in nerve conduction.

Food Sources

The main food sources are the protein food groups of meat and milk. A meal plan that provides adequate amounts of calcium and protein also provides an adequate amount of phosphorus.

Although whole-grain breads and cereals contain more phosphorus than cereals and breads made from refined flour, this is a storage form of phosphorus called phytin, which is not absorbed by humans.

Fruits and vegetables contain only small amounts of phosphorus.

Side Effects

There is generally no deficiency of phosphorus because it is so readily available in the food supply.

Excessively high levels of phosphorus in the blood, although rare, can combine with calcium to form deposits in soft tissues such as muscle. High levels of phosphorus in blood only occur in people with severe kidney disease or severe dysfunction of their calcium regulation.

Recommendations

According to Institute of Medicine recommendations, the recommended dietary intakes of phosphorus are as follows:

  • 0 to 6 months: 100 mg/day
  • 7 to 12 months: 275 mg/day
  • 1 to 3 years: 460 mg/day
  • 4 to 8 years: 500 mg/day
  • 9 to 18 years: 1,250 mg
  • Adults: 700 mg/day
  • Pregnant or lactating women:
    • Younger than 18: 1,250 mg/day
    • Older than 18: 700 mg/day
Lots More Information:
•Carbohydrates
•Fat
•Protein in diet
Review Date:1/2/2007
Reviewed By: William McGee, M.D., M.H.A., Assistant Professor of Medicine and Surgery, Tufts University School of Medicine, Boston, MA, and Chairman, Nutrition Committee, Baystate Medical Center, Springfield, MA. Review provided by VeriMed Healthcare Network.