For Professionals

Phosphorus

What is phosphorus?

Phosphorus, like potassium, is found in many foods and is important for many different functions in your body. The phosphorus that you eat is in the form of phosphates.

When you are on dialysis you will need to limit how much phosphorus (phosphates) you eat. You might need to start limiting phosphorus before starting dialysis. Ask your doctor or dietitian if you need to start limiting phosphorus.

What does phosphorus do?

Build bones and teeth

Provides energy

Comprises a part of DNA

High phosphorus (hyperphosphatemia)

How does high phosphorus cause damage?

Makes bones brittle

High phosphorus pulls calcium from your bones, making them weak and brittle.

Raises blood pressure

High phosphorus raises your blood pressure due to narrowed blood vessels from the calcium and phosphorus crystals.

Causes calciphylaxis

High phosphorus can lead to calciphylaxis. Calciphylaxis is a condition that consists of painful sores on the skin that can lead to infection.

Creates deposits in veins and organs

High phosphorus can cause the formation and deposit of a calcium and phosphorus structure in your veins and organs. Over time this can create bonelike crystals.

Makes bones brittle

High phosphorus pulls calcium from your bones, making them weak and brittle.

Raises blood pressure

High phosphorus raises your blood pressure due to narrowed blood vessels from the calcium and phosphorus crystals.

Causes calciphylaxis

High phosphorus can lead to calciphylaxis. Calciphylaxis is a condition that consists of painful sores on the skin that can lead to infection.

Creates deposits in veins and organs

High phosphorus can cause the formation and deposit of a calcium and phosphorus structure in your veins and organs. Over time this can create bonelike crystals.

Types of phosphorus

Your body absorbs phosphorus differently, depending on the type of food and whether it is natural phosphorus or added phosphorus in packaged or processed foods. It absorbs:

40% of grains

60% of meats, beans and nuts

80% of dairy

100% of added phosphorus

Foods with added phosphorus

Added phosphorus is used to preserve foods. It is commonly found in: 

  • Lunchmeat
  • Hot dogs
  • Pancake or biscuit mixes
  • Ranch dressing
  • Fast food
  • Colas
  • Tea (canned or bottled)
  • Powdered lemonade
  • Frozen foods
  • Tortillas
  • Many other types of
    packaged foods

Phosphorus as an additive

Because the body absorbs 100% of added phosphorus, it is very important to read the label on food items that come in a box, bag, or jar. This is also why it is always important to take your phosphate binders (medicines used to reduce the absorption of phosphates) if prescribed by your doctor, every time you eat. Phosphorus is difficult to find when looking on the food label. Go to the ingredient list to find added phosphorus and keep a list of the brands without added phosphorus to make shopping easier the next time.

A quick way to spot added phosphorus is to look for phosphates or “phos” in the ingredient list. Some examples include:

  • Phosphoric acid
  • Pyrophosphate polyphosphate
  • Hexametaphosphate
  • Dicalcium phosphate
  • Ferric phosphate
  • Sodium phosphate
  • Monocalcium phosphate
  • Aluminum phosphate
  • Sodium polyphosphate
  • Sodium tripolyphosphate
  • Sodium polyphosphate
  • Sodium tripolyphosphate
  • Trisodium phosphate
  • Tetrasodium phosphate

Be aware:

Phosphorus is added to many foods to help keep the food fresher. Our bodies absorb 100% of that added phosphorus. Phosphorus additives can be found in bagged, boxed, canned, or bottled foods. When you have kidney disease, you should avoid or limit foods with these additives. Look on the ingredient list to know if the item has added phosphorus.

Be aware:

Phosphates are the form of phosphorus found in your body. Phosphates are a large molecule made of phosphorus and oxygen. The large size of this molecule makes it hard to remove during dialysis. This is why it is important to take your phosphorus binders every time you eat, or drink a powdered, canned, or bottled beverage.

Low phosphorus (hypophosphatemia)

Having a low level of phosphorus is uncommon, but it can happen. If your phosphorus level is low, it might be because you do not have a good appetite and you are not eating enough, or you may be taking too many binders. Talk to your doctor or dietitian about how to keep your phosphorus at the right level. There are often no symptoms of low phosphorus.

If you have severely low phosphorus (phosphorus less than 1mg/dL), you could experience respiratory failure, heart failure, seizures, and/or coma.

Tips, webinars and videos

To learn more about managing your phosphorus in real-life situations, like shopping in a grocery store or eating in a restaurant, watch the following videos.

Phosphorus and dining out

Phosphorus and grocery shopping

Phosphorus and kidney disease

More Kidney Kitchen Resources