Thriving with Kidney Disease: A Fresh Look at Potassium

By Holly Dittmar, MS, RDN, CSR; Ellen Mohan, RD, CSR, CCTD; and Michael W. Holliday, Jr, MD, PhD, FASN

The content of this article reflects the personal experience and opinions of the authors and should not be
considered as medical advice or as a recommendation. The contents do not represent the views of, and are
not endorsed by, the U.S. Department of Veterans Affairs or the United States Government. Seek dietary
counseling that is specific to you from your healthcare provider and/or registered dietician.

Managing Potassium with Kidney Disease
Keeping your potassium level in a healthy range is important for many parts of your body. Potassium helps your cells, nerves, and muscles work properly, supports normal heart function, and plays a role in controlling blood pressure, blood sugar, and bone health. When it comes to potassium and kidney disease, there isn’t a one-size-fits-all diet. It is important to discuss your specific nutritional needs and limitations with your healthcare provider and dietitian. Some people have a tendency for a low blood potassium level (called hypokalemia)— either because of their kidney or gastrointestinal condition or because they take diuretic (“water pill”) medications. If you have hypokalemia, you may be encouraged to eat more potassium-rich foods or take a potassium supplement.

For many others with chronic kidney disease (CKD), the concern is the opposite. As kidney function declines, the body has a harder time
removing excess potassium that is absorbed from the diet. In addition, certain medications that help protect the kidneys—such as angiotensin-converting enzyme (ACE inhibitors; medications like lisinopril), angiotensin II receptor blockers (ARBs; medications like losartan), and mineralocorticoid receptor antagonists (MRAs; medications like spironolactone) —may raise potassium levels in the blood. Together, these factors increase the risk that potassium may become too high. A potassium level above 5.5 mEq/L is called hyperkalemia. When potassium becomes severely elevated, it can be lifethreatening and may cause abnormal heart rhythms. A potassium level of 5.1 mEq/L may indicate an increased risk of developing hyperkalemia and should be monitored closely.

Because of this risk, potassium is monitored closely in kidney care. Your healthcare team may recommend dietary changes and potassium lowering medications to help keep potassium within the normal range (about 3.5–5.2 mEq/L) and allow you to continue the medications for kidney protection. When it comes to potassium, what you eat truly matters. Your daily food choices can play a major role in keeping your potassium in a safe range— while also allowing you to continue medications that help protect your kidneys.

Potassium in Your Diet: What You Need to Know
Potassium is a mineral that shows up in many of the foods we eat every day. The body’s absorption and processing of dietary potassium is more complex than it appears. New research suggests that the total amount of potassium in your diet doesn’t always match the amount of potassium that is absorbed into your body.1 Instead, where your potassium comes from may influence how your body absorbs it and how it affects your health.

Understanding these differences can help you feel more confident about everyday food choices and better equip you to implement the dietary recommendations you receive from your healthcare providers.

Why Dietary Source Matters for Potassium Management
Many nutritious foods — such as fruits, vegetables, legumes, nuts, seeds, and whole grains — naturally contain potassium in variable amounts. How these foods are prepared may affect how much potassium your body absorbs and how quickly it enters your bloodstream. For a list of low- and high-potassium foods, please see the AAKP hyperkalemia webpage. Several factors help explain why potassium from different sources is absorbed differently in the body:
• Plant cell structure: In whole plant foods, potassium is stored inside plant cells. The cell walls act as barriers to naturally limit potassium absorption.2
• Fiber content: Whole plant foods are rich in fiber, which helps your body eliminate potassium through the digestive tract.3
• Alkaline effect: Fruits, vegetables and legumes are alkaline (the opposite of acid), which encourages potassium to move from the blood into the cells, helping keep blood potassium levels more stable.4

Processing of whole plant foods may change the absorption of certain nutrients. When fruits or vegetables are turned into juices, sauces, or purees, the plant cell walls and fiber are broken down. The loss of the plant cell structure results in potassium becoming more concentrated and more easily absorbed.5 Juices and smoothies are easier to consume quickly and in larger quantities, further increasing risk of higher potassium levels.
For example:
• One whole fresh orange has about 230 mg of potassium.
• One cup of orange juice has about 450 mg of more absorbable potassium.
Similarly,
• A medium whole tomato has around 200 mg of potassium.
• Half a cup of tomato sauce has about 450 mg of more absorbable potassium.
• Milk is also naturally rich in easily absorbed potassium. Consider choosing a lower potassium milk alternative such as a plant-based milk (rice or almond) without potassium or phosphorus additives.

Cooking Methods That Can Reduce Potassium
If you need to limit potassium, try these cooking strategies to reduce the potassium content of legumes and root vegetables by up to 50%.
• Legumes (beans, lentils): Rinsed, no salt added canned beans contain less potassium than beans cooked using traditional methods.6
If you prefer dried beans, soaking them before cooking can help reduce potassium. Soak dried beans for 12 hours in room temperature water or soak for 10 minutes in recently boiled water, then drain, rinse, and replace with fresh water before cooking.7
• Root vegetables (potatoes, sweet potatoes, beets): The “double boil” method has been shown to significantly reduce potassium. Peel and cube the vegetable into small pieces, boil for ten minutes, drain, then boil again in fresh water.3

Supplements: A Hidden Source of Potassium
Herbal products such as dandelion, horsetail, nettle, bitter melon, and noni naturally contain a significant amount of potassium. Some multivitamins include potassium as well. It is
important to check with your healthcare provider before starting any dietary supplement or herbal remedy.

Understanding Your Potassium Intake
The more we learn about potassium, the clearer it becomes that source matters just as much as amount. Whole plant foods tend to offer potassium in a form the body handles more gradually. Ultra processed foods and certain additives provide highly absorbable potassium that has a stronger effect on blood levels.

By getting familiar with where your potassium comes from, paying attention to food labels, and using helpful cooking methods, you can make choices that support your health without feeling restricted at every meal.

If potassium management is part of your care plan, your dietitian or healthcare provider can help you tailor these ideas to fit your specific needs and lifestyle.

This article was originally published in May/June 20026 issue of aakpRENALIFE magazine.