Potassium, Phosphorus, and Chronic Kidney Disease: How Much Can You Have?

Chronic Kidney Disease (CKD), Potassium, and Phosphorus

Chronic Kidney Disease (CKD), Potassium, and Phosphorus
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You’ve probably heard that you should be mindful of your sodium intake to maintain the health of your kidneys, but some people with chronic kidney disease (CKD) may have to pay close attention to their potassium and phosphorus consumption as well. As CKD progresses, the kidneys lose their ability to filter out these essential minerals, potentially leading to additional symptoms and disease complications.

There isn’t one guideline that applies to everyone with CKD regarding how much potassium and phosphorus are safe. Recommendations differ depending on the individual, their stage of kidney disease, and their overall health. If you’re unsure how much potassium and phosphorus you should be consuming, consult your nephrologist, as well as a registered dietitian-nutritionist, for individualized guidelines.

Potassium and CKD

Potassium is an essential mineral that your body uses to maintain kidney, heart, muscle, and nerve health.

 But too much can be problematic.

“Excess potassium concentrations can result in cardiac arrhythmias,” says Sumit Mohan, MD, a transplant nephrologist at NewYork-Presbyterian/Columbia University Irving Medical Center in New York City. “That’s the real worry with having a diet rich in potassium, since patients with CKD have an impaired ability to excrete potassium, especially in advanced stages.”

Potassium: The Expert Guidelines

Guidelines suggest consuming a total of 2 to 3 grams (g) of potassium per day, says Dr. Mohan.

If you have an early stage of CKD and no history of elevated potassium levels, Mohan says that restricting potassium isn’t recommended. With that said, he points out that some medications raise potassium levels in the blood, including those that treat high blood pressure, so people with CKD are encouraged to talk to their doctor about managing this risk and whether that may change their potassium needs.

What Foods Have the Most Potassium?

Although plant-based foods like fruits and vegetables have lots of potassium, the body absorbs only about half of it, so high-potassium ingredients like bananas or spinach may not be as bad as they seem.

But you should be especially careful to limit animal-based proteins and processed foods, which are absorbed more readily and more likely to cause problems in CKD.
High-potassium foods and ingredients include the following choices:

  • Breaded chicken
  • Chocolate
  • Chocolate milk
  • Coconut water and coconut milk
  • Coffee (limit to 2 cups per day)
  • Dairy and soy milk
  • Dried fruit
  • Fruit and vegetable juice
  • Low-sodium processed foods like canned soup and pickles
  • Potassium additives, such as potassium chloride, potassium phosphate, potassium lactate, and potassium citrate
  • Potatoes, chips, and french fries
  • Powdered drink mixes
  • Processed meat (ham, hot dogs, bacon, deli meat)
  • Sports drinks
  • Tomato sauce and soup

Phosphorus and CKD

While phosphorus is primarily stored in your bones and teeth, the essential mineral is found in every cell of the body.

 And like potassium, phosphorus can become a problem if you have CKD.

“When kidney function is impaired, excess phosphorus can accumulate in the blood, triggering the body to pull calcium from the bones,” says Los Angeles-based Jamie Mok, RD, a spokesperson for the Academy of Nutrition and Dietetics. The result can weaken bones and prompt calcium deposits in blood vessels and the heart, which can lead to heart attack and stroke, she says.

Phosphorus: The Expert Guidelines

Phosphorus recommendations depend on disease severity.

“We recommend limiting phosphorus intake, especially in people with advanced CKD,” says Mohan. A phosphorus-reduced diet typically allows 800 to 1,000 milligrams (mg) of the mineral per day, says Mok.

“Keep in mind that nutritional needs change depending on your stage of kidney disease and other health conditions you may have, so it’s important to work closely with your healthcare team and a registered dietitian to create a plan that’s right for you,” says Mok.

What Foods Have the Most Phosphorus?

Phosphorus is found in many healthy ingredients, such as dairy, eggs, fish, grains, legumes, meats, nuts, seeds, and vegetables.

These foods contain organic phosphorus, which is not completely absorbed by the body, though the phosphorus in animal-based foods is absorbed more easily than that from plant-based foods.

Inorganic phosphorus, which appears in processed foods as an additive, is more concerning. “Because the body absorbs nearly 100 percent of phosphorus additives found in processed foods such as soft drinks and fast food, these should be the first items avoided,” says Mok.

How to Avoid Excess Potassium and Phosphorus

Since the minerals found in meats and processed foods are more likely to contribute to health problems, a healthy plant-based diet is considered one of the best dietary strategies for managing CKD.

“In general, I advise my patients to focus on whole, minimally processed foods while prioritizing portion size, variety, and their own individual needs and preferences,” says Mok.

If your doctor and renal dietitian have recommended a potassium-restricted diet, Mok advises prioritizing lower-potassium fruits and vegetables like apples, berries, and green beans, and eating smaller portions. As for phosphorus, she says the most impactful thing you can do is reduce your intake of processed foods with phosphorus additives.

For people with CKD who feel overwhelmed or restricted by nutritional recommendations, Mok recommends meeting with a registered dietitian-nutritionist who can help you liberalize your food choices.

“By focusing on what you can have, we help you overcome the diet fatigue so often caused by the restrictive nature of medically prescribed diets, like a traditional kidney disease diet,” she says.

The Takeaway

  • Dietary guidelines for potassium and phosphorus aren’t universal; a nephrologist and nutritionist can tell you your limits based on your stage of CKD, medications, and overall health.
  • Experts generally recommend a daily limit of 2 to 3 g of potassium for those at risk, advising people with CKD to prioritize plant-based foods over more readily absorbed animal proteins and processed foods containing potassium additives.
  • Since excessive phosphorus can leach calcium from bones into the bloodstream, people with CKD are often advised to limit their phosphorus intake to 800 to 1,000 mg per day, specifically avoiding processed foods that contain inorganic phosphorus additives.
  • A plant-based diet focusing on whole, minimally processed foods is a primary strategy for managing one’s potassium and phosphorus levels, with an emphasis on choosing lower-potassium produce and reducing phosphorus additives.

Resources We Trust

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Potassium. National Institutes of Health Office of Dietary Supplements. March 22, 2021.
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. International Society of Nephrology. April 2024.
  3. Hyperkalemia (High Potassium). Cleveland Clinic. May 11, 2023.
  4. Potassium Management in Kidney Disease. BCRenal. March 2023.
  5. Phosphorus. National Institutes of Health Office of Dietary Supplements. March 22, 2021.
  6. Phosphorus and Your CDK Diet. National Kidney Foundation. July 16, 2024.
igor-kagan-bio

Igor Kagan, MD

Medical Reviewer

Igor Kagan, MD, is an an assistant clinical professor at UCLA. He spends the majority of his time seeing patients in various settings, such as outpatient clinics, inpatient rounds, and dialysis units. He is also the associate program director for the General Nephrology Fellowship and teaches medical students, residents, and fellows. His clinical interests include general nephrology, chronic kidney disease, dialysis (home and in-center), hypertension, and glomerulonephritis, among others. He is also interested in electronic medical record optimization and services as a physician informaticist.

A native of Los Angeles, he graduated cum laude from the University of California in Los Angeles (UCLA) with a bachelor's in business and economics, and was inducted into the Phi Beta Kappa honor society. He then went to the Keck School of Medicine at the University of Southern California (USC) for his medical school education. He stayed at USC for his training and completed his internship and internal medicine residency at the historic Los Angeles County and USC General Hospital. Following his internal medicine residency, Kagan went across town to UCLA's David Geffen School of Medicine for his fellowship in nephrology and training at the UCLA Ronald Reagan Medical Center. After his fellowship he stayed on as faculty at UCLA Health.

Jessica Migala

Author

Jessica Migala is a freelance writer with over 15 years of experience, specializing in health, nutrition, fitness, and beauty. She has written extensively about vision care, diabetes, dermatology, gastrointestinal health, cardiovascular health, cancer, pregnancy, and gynecology. She was previously an assistant editor at Prevention where she wrote monthly science-based beauty news items and feature stories.

She has contributed to more than 40 print and digital publications, including Cosmopolitan, O:The Oprah Magazine, Real Simple, Woman’s Day, Women’s Health, Fitness, Family Circle, Health, Prevention, Self, VICE, and more. Migala lives in the Chicago suburbs with her husband, two young boys, rescue beagle, and 15 fish. When not reporting, she likes running, bike rides, and a glass of wine (in moderation, of course).