Potassium with Kidney Disease: Is it Good or Bad?

Should you avoid high potassium foods because of your kidney disease? 

I’m here to help you figure that out by discussing everything you need to know about potassium and kidney disease!

My name is Candace Mooney and I’m a registered dietitian and a board certified specialist in renal nutrition. 

Let’s get started!

What is potassium?

Potassium is a mineral and an electrolyte found in food that helps your body function in many different ways.

It is important that you eat enough potassium to help maintain normal heart function, normal blood pressure levels, and normal reactions throughout the body. (1)

Is Potassium Bad for Kidney Disease?

When your kidneys aren’t functioning at 100%, potassium can build up in your blood. This can cause hyperkalemia (high potassium).

Hyperkalemia does not always present with symptoms, but it can cause weakness, nausea, or muscle pain. High potassium in your blood can also cause abnormal heartbeat. Sometimes you can get diarrhea, as your body is trying to remove extra potassium when your kidneys can’t do it for you. (2, 3)

High potassium levels can also make you retain more fluid. This causes your body to work harder. Extra fluid can increase your blood pressure, causing more damage to your arteries and heart because you’re moving around that extra fluid. 

If your blood pressure is consistently high, this can cause small tears in your blood vessels. When this happens, your body sends cells to help repair these tears, but substances like cholesterol can build up at these tears. This can cause your arteries to become narrow, which can cause blood flow to be blocked.(4) 

Recommended potassium intake for CKD (Chronic Kidney Disease) stages 3-5: 2,000-4000 mg per day when hyperkalemia is present. (5)

These are all reasons why you may want to limit your potassium, but how do you know if you specifically need to limit your potassium? There are many things, other than food, that can influence potassium levels, so let’s look at those now.

Do you need to limit your potassium?

When I start to ask this question with my patients, a few things I like to look at first are lab values, medications, comorbidities, and dietary patterns. This is because potassium levels can be influenced by medications, hydration, acid-base status, glycemic control, adrenal function, catabolic state, or gastrointestinal problems. (6)

Labs

Lab values are an easy way to tell if your potassium is within a normal range. The recommended range for potassium with kidney disease is 3.5-5.0 mEq/L. (7)

So, if your potassium is within a normal range during your lab draws, great! There’s no need to make adjustments to your food choices in regard to potassium. 

If your potassium levels are out of range, you may want to discuss some of these considerations below with your healthcare team.

Medication Management

Some blood pressure medications can cause your potassium levels to be high. ACE inhibitors (anything that ends in -pril) and ARBS (anything that ends in -sartan) have the potential to cause hyperkalemia. It’s important you discuss your medications with your doctor. (8) 

Medications like potassium binders and diuretics can help lower your potassium levels. If your potassium level is low while on a potassium binder or diuretic, you may need to discuss this with your healthcare team.

Managing Comorbidities

Comorbidities occur when two or more medical conditions are present at the same time. For example, if you have kidney disease, diabetes, and hypertension, you have comorbidities.

Metabolic Acidosis

Metabolic acidosis can cause hyperkalemia. 

Managing the amount of acid in your body, can also help keep your potassium within normal range. Sodium bicarbonate is one medication you may be taking to help with metabolic acidosis. 

Choosing lower PRAL (potential renal acid load) foods can also help reduce the amount of acid in your body because they produce alkali (a base). (9)

Check out our blog on PRAL for more in depth discussions of these foods.

Constipation 

Constipation can cause reabsorption of potassium through your stool. Make sure you are stooling regularly (at least once every day or every other day) and fully emptying your bowels.

Diabetes

Your kidneys help regulate your blood sugar by filtering your blood and either excreting glucose through urine or reabsorbing it as needed. 

If your kidneys are not working as they should, this could lead to insulin resistance, which causes hyperglycemia (high blood sugar) and hyperinsulinemia (high insulin in your blood). (10)

Uncontrolled diabetes can damage the kidneys, preventing them from filtering out potassium. Hyperinsulinemia can cause potassium to be pulled into your blood from your cells. Both of these could be a cause for your high potassium level.

You may want to consult with your healthcare team, but one way to help manage your diabetes is through a consistent carbohydrate diet. (11) This means consuming the same amount of carbs at every meal to avoid spikes or drops in blood sugar, thus keeping your blood sugar more tightly regulated. 

Here’s an easy to follow flow chart when trying to initiate a plan of action for hyperkalemia when you have kidney disease:

If your medications and comorbidities are managed well, then you may want to start learning how to manage potassium within your diet. Limiting your dietary potassium may help in the short term while trying to figure out the above with your healthcare team.

Dietary Potassium with Kidney Disease

Potassium is an important mineral in a healthy diet. I typically recommend you eat as much potassium as possible because of the health benefits of a higher potassium diet.

But, in kidney disease, sometimes too much potassium can be harmful. 

Potassium can be found in many different foods and beverages so we’ll talk about how to identify which foods have potassium, how much potassium, and what kind of potassium below.

Potassium Additives and Natural Potassium

There are 2 types of potassium: potassium additives and naturally occurring potassium.

Potassium additives have been added to foods to enhance the flavor, color, or texture. (12) Some examples of potassium additives are potassium phosphate, potassium lactate, potassium chloride, and potassium citrate.

Potassium additives may be a hidden source causing your hyperkalemia. I typically recommend avoiding potassium additives.

Here are some examples of foods containing a potassium additive. It will be listed in the ingredient list and will contain the word potassium.

Salt Substitutes

Beware of salt substitutes because they will commonly use potassium in place of sodium!

It is important to look at the ingredients (as above) on the food label to determine if your salt substitute contains potassium.

Examples of potassium free salt substitutes are: Mrs. Dash (multiple options), Lawry’s Salt Free 17 seasoning, Flavor God (multiple options).

Check out our Spice up Kidney Disease post for more information about other kidney-friendly seasoning options and ideas.

Foods that Contain Natural Potassium

Potassium that is found naturally in foods does not raise your blood potassium like potassium additives because it is less bioavailable making it harder for your body to absorb. 

These foods also contain beneficial fiber and micronutrients like vitamins and phytochemicals that could help with kidney disease. (13)

Here are some examples of foods that are high and low in potassium: (14)

Reducing Potassium through Cooking

I don’t know about you, but potatoes are one of my favorite comfort foods! If you’re in the same boat as me, there are several ways to reduce potassium in your favorite foods.

Peeling, soaking, and double boiling potatoes and other high potassium foods can help remove potassium. Unfortunately, the techniques and percentage of removal for soaking and boiling are not well defined. (15, 16)

You can also drain and rinse canned fruits and vegetables with water to help remove excess potassium from the liquid they were canned in. This will help remove some sodium, too.

Pressure cooking can also help remove some of the potassium in meats. (17)

Summary

There are several reasons you could be struggling with hyperkalemia that don’t involve high potassium foods.

If you find that you do need to reduce potassium in your diet, my first line of defense is always to cut out potassium additives. 

Remember that potassium is essential for many bodily functions, so it is important that you still choose potassium foods as much as you can!

If you’re not sure how much potassium you should eat, reach out to your healthcare team. You can also reach out to me or other renal dietitians to learn more about working one on one with us.

This article was co-written by dietetic intern Loren Jett & reviewed, edited, and co-written by Candace Mooney, MS RDN CSR.