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?
Builds bones and teeth
Comprises a part of DNA
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.
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.
High phosphorus can lead to calciphylaxis. Calciphylaxis is a condition that consists of painful sores on the skin that can lead to infection.
Types of phosphorus
Your body absorbs phosphorus differently from different foods.
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:
Foods with added phosphorus
Added phosphorus is used to preserve food. It is commonly found in:
- Hot dogs
- Pancake or biscuit mixes
- Ranch dressing
- Fast food
- Tea (canned or bottled)
- Powdered lemonade
- Frozen foods
- 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.
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.
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
- Dicalcium Phosphate
- Ferric Phosphate
- Sodium Phosphate
- Monocalcium Phosphate
- Aluminum Phosphate
- Sodium Polyphosphate
- Sodium Tripolyphosphate
- Sodium Polyphosphate
- Sodium Tripolyphosphate
- Trisodium Phosphate
- Tetrasodium Phosphate
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.
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.
Managing your phosphorus levels
Keep a list of your favorite foods that do not have added phosphorus.
Check these products at least once a year (just in case the ingredients change).
Check nutrition labels for added phosphates.
The closer to the top of the ingredient list, the higher the phosphorus in the product. The more types of added phosphorus in the product, the more phosphorus it has.
Always carry your phosphate binders with you, especially when you are going out to eat.
Try to keep them in places where you eat: kitchen table, couch, dining room, etc.
Take your phosphate binders 5-10 minutes before you eat.
Choose grilled rather than breaded or fried foods. The breading has added phosphorus.
Cook at home.
Talk with your dietitian if your phosphorus unexpectedly rises.
Low phosphorus recipes with Chef Joel Schaefer
The strict diet that chronic kidney disease patients must follow includes foods that are low in phosphorous. Chef Joel Schaefer is an expert in cooking healthy foods that meet special dietary needs.
Tips on managing your phosphorus
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.