Phosphorus and Your Kidneys

Phosphorus is a mineral that is found in your bones and that is also found in many foods that we eat. Along with other minerals and vitamins such as calcium and vitamin D, the body uses phosphorus to build strong bones and to stay healthy.

Healthy kidneys are able to regulate the amount of phosphorus in the body by removing extra phosphorus found in the blood through the filtration process. Kidneys affected by chronic kidney disease (CKD) are not able to remove phosphorus effectively which can damage the body in many ways.

It’s important that those with kidney damage actively monitor the amount of phosphorus in their diet because the buildup of phosphorus in the blood can weaken bones and damage the eyes, blood vessels, lungs and heart. Many individuals with chronic kidney disease are prescribed medicines to help control the amount of phosphorus in the body. These medicines are known as “phosphate binders” and are taken with meals and snacks to help control the amount of phosphorus the body absorbs from food during digestion. While phosphate binders help with phosphate control, to work optimally, they must be used along with dietary control. So those with kidney disease need to also pay attention to the amount of phosphorus they are consuming through eating and drinking.

It may sound like an easy dietary restriction, but this is where it gets tricky. Unlike other components of foods we eat, such as the amount of salt (sodium), fat or sugar found in packaged foods, the U.S. Food and Drug Administration (FDA) does not currently require that the amount of phosphorus in foods is clearly listed on the nutrition label. That means that to be an informed consumer, simply reading the packaging is not always enough to ensure that you’re adequately limiting your phosphorus intake. Some manufacturers choose to provide this information while others do not.

Speaking with your doctor and renal dietitian is critical to creating a dietary plan that appropriately restricts the amount of phosphorus you take in. Additionally, memorizing which foods are considered high and low phosphorus foods or keeping a journal with this information can be very helpful in making healthy, kidney friendly food choices.

Phosphorus is found both naturally in certain foods and in the form of additives to help foods taste better, look better and last longer on the shelves. The body readily absorbs phosphorus that has been added to foods during processing, making it even more important to find out exactly what you’re putting in your mouth. There are some key food categories that are often modified with added phosphorus and it’s important to look out for them, especially when eating packaged, convenience foods. These include processed dairy, beverages, deli meats, and cereals. While these reflect some broad categories, it’s important to keep in mind that any food that has undergone processing may contain high levels of phosphorus.

For example, many meat products are “enhanced” or altered with added salts including forms of phosphorus such as phosphate salts to improve flavor, shelf life and tenderness. Additionally, certain types of cereals, oatmeal products, whole grains, breakfast bars and granola-type snack bars contain high levels of phosphorus. Dark colored colas and certain juices and teas also have higher levels of phosphorus than others.

For more information on phosphorus control in chronic kidney disease, as well as, specific high phosphorus foods, and low phosphorus alternatives, click here.