What is phosphorus and why is it important?

Phosphorus is the second most plentiful mineral in your body. The first is calcium. Your body needs phosphorus for many functions, such as filtering waste and repairing tissue and cells.

Most people get the amount of phosphorus that they need through their daily diets. In fact, it’s more common to have too much phosphorus in your body than too little. Kidney disease or eating too much phosphorus and not enough calcium can lead to an excess of phosphorous.

However, certain health conditions (such as diabetes and alcoholism) or medications (such as some antacids) can cause phosphorus levels in your body to drop too low.

Phosphorus levels that are too high or too low can cause medical complications, such as heart disease, joint pain, or fatigue.

You need phosphorus to:

  • keep your bones strong and healthy
  • help make energy
  • move your muscles

In addition, phosphorus helps to:

  • build strong teeth
  • manage how your body stores and uses energy
  • reduce muscle pain after exercise
  • filter out waste in your kidneys
  • grow, maintain, and repair tissue and cells
  • produce DNA and RNA — the body’s genetic building blocks
  • balance and use vitamins such as vitamins B and D, as well as other minerals like iodine, magnesium, and zinc
  • maintain a regular heartbeat
  • facilitate nerve conduction

Most foods contain phosphorus. Foods that are rich in protein are also excellent sources of phosphorus. These include:

  • meat and poultry
  • fish
  • milk and other dairy products
  • eggs

When your diet contains enough calcium and protein, you’ll likely have enough phosphorus. That’s because many of the foods that are high in calcium are also high in phosphorous.

Some non-protein food sources also contain phosphorus. For example:

  • whole grains
  • potatoes
  • garlic
  • dried fruit
  • carbonated drinks (phosphoric acid is used to produce the carbonation)

Whole grain versions of bread and cereal contain more phosphorus than those made from white flour.

However, phosphorus in nuts, seeds, grains, and beans is bound to phytate, which is poorly absorbed.

The amount of phosphorus you need in your diet depends on your age.

Adults need less phosphorus than children between the ages of 9 and 18, but more than children under age 8.

The recommended dietary allowance (RDA) for phosphorus is the following:

  • adults (ages 19 years and older): 700 mg
  • children (ages 9 to 18 years): 1,250 mg
  • children (ages 4 to 8 years): 500 mg
  • children (ages 1 to 3 years): 460 mg
  • infants (ages 7 to 12 months): 275 mg
  • infants (ages 0 to 6 months): 100 mg

Few people need to take phosphorus supplements. Most people can get the necessary amount of phosphorus through the foods they eat.

Too much phosphate can be toxic. An excess of the mineral can cause diarrhea, as well as a hardening of organs and soft tissue.

High levels of phosphorus can affect your body’s ability to effectively use other minerals, such as iron, calcium, magnesium, and zinc. It can combine with calcium causing mineral deposits to form in your muscles.

It’s rare to have too much phosphorus in your blood. Typically, only people with kidney problems or those who have problems regulating their calcium develop this problem.

Some medications can lower your body’s phosphorus levels. Examples include:

Symptoms of low phosphorus can include:

  • joint or bone pain
  • loss of appetite
  • irritability or anxiety
  • fatigue
  • poor bone development in children

If you take these medications, talk to your healthcare provider about whether it’s recommended that you eat foods high in phosphorus or take phosphorous supplements.