Phosphorus

Phosphorus

Functions

Probably no mineral element has more functions than phosphorus. It is essential for the formation of

·           bones and teeth.

·           phospholipids that regulates the absorption and transport of fats.

·           DNA and RNA, which are nucleic acids essential for protein synthesis and genetic coding.

·           ATP and ADP, which are necessary for storing and releasing energy according to the body needs.

·           enzymes that are required to metabolise carbohydrates, fats, and proteins and buffer salts in the regulation of acid-base balance.

Blood content of phosphorus

The inorganic phosphorus content of blood in normal human adults ranges from 2.5 to 4.0 mg /100 ml and in children from 4 to 5 mg/ 100 ml.

Sources

This element is found in both animal and plant foods. Animal sources include fish, meat, egg, milk, liver and kidneys. Plant sources of phosphorus are nuts, beans, green vegetables and fruits. A diet which is adequate in calcium is usually adequate in phosphorus also.

Requirements

Infants - 0.24-0.4 g/day

Children - 0.8 -1.2 g/day

Adults - 0.8 g/day

During pregnancy and lactation - 1.5 g/day

Absorption and excretion

Moderate amounts of fatty acid favour absorption of phosphorus. High calcium content in diet decreases the absorption of phosphorus. Phosphorus is excreted in the urine and feces.

Deficiency

A deficiency of phosphorus leads to rickets. Low level of blood phosphorus characterised by defective bone and teeth formation.