Kidney Diet Tips

Reading Food Labels to Identify Hidden Phosphorus

Understanding food labels is even more important for those following a kidney diet. Since phosphorus is often missing from the Nutrition Facts, it’s important to know how to find hidden sources on the ingredient list.

Look for obvious sources of phosphorus in the ingredients: cheese, milk, yogurt, nuts, seeds, dried beans and peas, bran, whole wheat or whole grains, organ meats, peanut butter and chocolate.

One not-so obvious source of phosphorus is the leavening agent, baking powder. One teaspoon contains over 450 mg phosphorus and over 350 mg sodium. Products made with baking powder include biscuits, pancake mix, quick breads and many commercially prepared bakery products.

Cereals and cereal bars may be another phosphorus contributor. Many cereal boxes list phosphorus in mg or as a % of Daily Value (DV). Use these numbers to interpret:
50 mg or up to 5% DV is low phosphorus
51-150 mg or 5-15% DV is medium phosphorus
Over 150 mg or greater than 15% DV is high phosphorus

Another hidden source of phosphorus is enhanced meats. These products look like fresh meats but have been injected with a solution of water, sodium, potassium, phosphates and antioxidants to help retain fresh appearance, extend shelf life and retain moisture during preparation.

A growing number of foods are showing up with phosphate additives. Several years ago you could safely buy canned or bottled tea, punch or lemonade without worrying about phosphorus. Kidney patients were instructed to avoid colas due to phosphoric acid, but most other sodas were safe. Now some brands of soda, tea, punch and lemonade contain phosphate additives which are almost 100% absorbed. Manufacturers use phosphorus containing additives as buffers, dough conditioners, anti-caking agents, emulsifiers, texturizers, acidifiers and dietary supplements (most foods with added calcium contain calcium phosphate). It is extremely important to read the ingredient list of any processed food to identify hidden phosphorus. Look for terms like polyphosphate, phosphoric acid, calcium phosphate and pyrophosphate and avoid these products.

For more information on phosphorus and label reading check out this DaVita.com article:

Reading labels to control phosphorus in the dialysis diet

Sara Colman, RD, CDE

Sara Colman, RD, CDE

Sara is a renal dietitian with over 20 years experience working with people with diabetes and kidney disease. She is co-author of the popular kidney cookbook "Cooking for David: A Culinary Dialysis Cookbook". Sara is currently the Manager of Kidney Care Nutrition for DaVita. She analyzes recipes and creates content, resources and tools for the kidney community. In her spare time Sara loves to spend time with her young grandson, including fun times together in her kitchen.