Phosphorus is the second most abundant mineral in the body, after calcium. There is not one main function of phosphorus. Eighty-five percent of phosphorus in the body is found in bones, and the remaining 15 percent is spread throughout soft tissues. It is essential for the normal function of every cell, performing a variety of functions. Phosphorus is absorbed in the small intestine and stored in bones. Excess phosphorus is excreted by the kidneys. Because phosphorus occurs in many foods, deficiency is rare.
Bones and Teeth
Phosphorus works closely with calcium to build strong bones and teeth. These two minerals combine to form calcium phosphate, the predominant mineral of bone. Adequate intake of phosphorus and calcium is essential in utero and during childhood and puberty, when bone mass is laid down. For adult women, requirements increase again during pregnancy and lactation and in postmenopause, when the protective effect of estrogen on bone is depleted. It is important to have a balance of phosphorus and calcium in the diet. Having more phosphorus than calcium may lead to osteoporosis and gum and teeth problems.
Phosphorus also combines with lipids – usually diglyceride – to form various types of phospholipids. Phospholipids are a major structural component of all cell membranes, or walls, throughout the body. They are essential for optimal brain health, helping brain cells communicate and influencing receptor function. Phospholipids in brain cells also control which minerals, nutrients and drugs go in and out of the cell.
Phosphorus has many other essential functions. It is required for energy production and storage, helping your body change protein, fat and carbohydrate into energy. As a component of DNA and RNA, phosphorus is also involved in the storage and transmission of genetic material. It activates enzymes, hormones and cell-signaling molecules through phosphorylation. Phosphorus also helps get oxygen to tissues and maintain normal acid-base, or pH, balance by acting as a buffer.
The recommended intake for phosphorus is 1,000 mg daily. Average daily intake in the United States is 1,024 mg for women and 1,495 mg for men. Phosphorus is widespread in the diet. Animal products such as milk, yogurt, cheese, eggs, meat and fish are rich sources. Plant sources include dried peas and beans, nuts, seeds and nut butters, brown and wild rice, whole-grain breads and cereals. The phosphorus from animal products is absorbed more easily than that found in cereal grains.