Role of Phosphorus

Phosphorus is a negatively charged intracellular electrolyte that is present in our bodies as part of a chemical group called a phosphate group. These phosphate groups are essential as a structural component of cell membranes (as phospholipids), DNA and RNA, energy production (ATP), and regulation of fluid balance and acid-base homeostasis.  Phosphorus, however, is mostly associated with calcium as a part of the mineral structure of bones and teeth.  Blood phosphorus levels are not controlled as strictly as blood calcium levels, as the PTH stimulates renal excretion of phosphate so that it does not accumulate to toxic levels.

Dietary Reference Intakes for Phosphorus

Unlike with calcium, most people are not at risk of a phosphate deficiency. The RDA is 700 milligrams per day. The UL set for phosphorous is 4,000 milligrams per day for adults and 3,000 milligrams per day for people over the age of seventy.

Dietary Sources of Phosphorus

Phosphate is present in many foods popular in the North American diet including meat, fish, dairy products, processed foods, and beverages. Phosphate is added to many foods because it acts as an emulsifying agent, prevents clumping, improves texture and taste, and extends shelf-life.

Consuming Too Little Phosphorus

Phosphorus deficiency is rare, however, those who suffer from alcoholism, premature infants, the elderly with a poor diet, and those with a vitamin D deficiency may be at risk of low blood phosphorus levels.

Consuming Too Much Phosphorus

Phosphorus toxicity is rare, however, those with kidney disease or those who are taking too many vitamin D supplements or phosphorus-containing antacids may be at risk. Very high blood levels of phosphorus can result in muscle spasms and convulsions.