Phosphorus

What is phosphorus?

Phosphorus (commonly found in nature as phosphate) is an essential component of all cells. More than 85% of the phosphorus in the adult body is found in the bones. In fact, more than half of all bone is made up of phosphorus. The remaining 15% is found in soft tissues of the body. Phosphorus is a major component of most cells in the body. It is used to maintain acid-base balance, involved in energy production, and necessary for other vital cellular functions. Dietary phosphorus is necessary to support growth (during youth, pregnancy and lactation) and to replace daily phosphorus losses.

How much phosphorus is recommended each day?

The Recommended Dietary Allowance (RDA) for phosphorus is the average daily dietary intake needed to meet the requirements of most individuals.

RDA for Phosphorus

What foods are high in phosphorus?

Food sources of phosphorus occur both naturally and as food additives (phosphate salts) used in processed foods to add moisture, smoothness and as a binding agent. Foods that are high in phosphorus include milk (234mg per 8 ounces), milk products, poultry, fish, meat, eggs, grains and legumes. Certain sodas that use phosphoric acid as an ingredient (colas and a few others) have a small amount of phosphorus added (less than 50mg per 12 ounces). Of the phosphorus sources, only milk (and milk products) also contain high amounts of calcium.

For more information about the phosphorus content of selected foods, click on the USDA National Nutrient Database listed according to phosphorous content or listed alphabetically.

Is drinking soda bad for my bones?

In general, the negative impact of soda on bone health is not due to the phosphorus content of the soda. Instead the detrimental effect of soda on bones occurs because calcium-containing beverages are often omitted in favor of soda. Soda is a nutrient-poor beverage that often replaces other potentially nutrient-rich beverages such as milk, fortified soy milk or calcium-fortified juices. The low calcium intake is what's bad for your bones.

It is concerning that soda consumption is on the rise among our nation's youth and this is occurring during the years (age 9-18) when calcium needs for building bone are the highest. In addition, the extra calories contained in (non-diet) sodas may contribute to the problem of obesity among youth that is at an all-time high. Many schools have initiated campaigns to replace soda machines in schools with alternative, nutritious beverages. For more information, click on the following website: California Project Lean and 3-A-Day for Better Bones.

Can I consume too much phosphorus in my diet?

The maximum safe intake of phosphorus for adults is 4000mg per day. This amount is very rarely consumed in the U.S. population and could only be reached by using excessive amounts of phosphorous supplements in addition to a typical diet.

Is it true that too much phosphorous can interfere with calcium absorption?

When calcium intake is adequate, a high phosphorus intake is not detrimental to calcium absorption. The ratio of calcium to phosphorus is probably more important than the amount of phosphorus in the diet alone. Milk and dairy products have a balanced ratio of calcium to phosphorus that results in good absorption of both nutrients and a favorable effect on bone health.

Is phosphorus deficiency common ?

Phosphorus is so plentiful in the food supply that deficiency does not occur in the healthy population. Phosphorus deficiency is rare and occurs secondary to other conditions rather than dietary intake. For example, phosphorus deficiency can result from poorly managed diabetes (diabetic ketoacidosis), during recovery from alcoholism, from high dose antacid use, and in other conditions associated with malnutrition. Phosphorus deficiency is easily diagnosed by a medical professional and is important to treat. Untreated phosphorus deficiency could lead to an increased risk for fracture.