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
Age (years)Phosphorus (mg*)
      9-18         1250
19 and over          700
*mg = milligrams

For more information about the phosphorus content of selected foods, click on the link below from USDA, National Agricultural Library:

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 (234 milligrams in 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 50 milligrams in 12 ounces). Of the phosphorus sources, only milk (and milk products) also contain high amounts of calcium.

Both calcium and phosphorus are found naturally in dairy products, but many calcium supplements and calcium-fortified foods and beverages do not contain much phosphorus. 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?

There is limited research available on the impact of dietary phosphorus on bone health. The Framingham study showed that higher intake of cola beverages was associated with lower bone density in women but not men. Cola may be more detrimental to bones than other soft drinks. Though further research is needed, the negative impact of soda on bone health seems less due to the phosphorus content of the soda. Instead, the detrimental effect of soda on bones occurs when calcium-containing beverages are omitted from the diet in favor of soda. Soda is a nutrient-poor beverage that often replaces other nutrient-rich beverages such as milk, fortified soy beverages, or calcium-fortified juices. We know that low calcium intake is harmful for your bones. Consuming the recommended amount of calcium is necessary to attain peak bone mass in youth and prevent bone loss at older ages.

Can I consume too much phosphorus in my diet?

The maximum safe intake of phosphorus for healthy adults under age 70 is 3000 mg per day and 4000mg per day for adults over age 70. 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 the recommended calcium intake is consumed, 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 has a positive impact on bone health.

Is phosphorus deficiency common?

Phosphorus is plentiful in the food supply and deficiency does not occur in the healthy population. Phosphorus deficiency is rare and occurs as a result of other conditions rather than due to limited phosphorus intake from foods. For example, phosphorus deficiency can result from poorly managed diabetes (diabetic ketoacidosis), during recovery from alcoholism, from high dose antacid use, and in conditions associated with malnutrition. Phosphorus deficiency is easily diagnosed by a healthcare provider and is important to treat. Untreated phosphorus deficiency may lead to an increased risk of broken bones.