The Power of Potassium: Why You Need This Essential Mineral

When you think of potassium, you probably think of bananas… and not much else. But there’s so much more to know about this essential mineral, which is found in many other foods and plays a few roles in your body.

“Potassium helps with fluid balance in the cells, which supports normal blood pressure,” says registered dietitian Julia Zumpano, RD, LD. “It also works with sodium to balance the fluid outside of the cells.”

What are the benefits of potassium?

Potassium is critical to the way your body functions. For starters, it acts as an electrolyte, which means that it carries an electrical charge — in this case, a positive one. There are different types of electrolytes, and each performs a different function in your body.

• Balance the fluid in your cells.
• Contract muscles (including your heart).
• Transmit nerves signals to your brain.

What does all of that mean for you, exactly? Let’s break down those benefits.

Acts as a counterpart to sodium

There are seven key elements your body needs to maintain normal electrolyte levels. Potassium is one of them; sodium (salt) is another. But too much sodium is known to have negative effects on the body — and potassium can help.

"A potassium-rich diet blunts the effects of salt on blood pressure,” Zumpano says. “It may also reduce your chances of developing kidney stones or bone loss from aging."

Balances fluid in your body

Electrolytes help keep the fluids inside your body in balance.

Think about it: When your child gets off the soccer field, having seemingly sweated out their body weight in perspiration, you give them an electrolyte drink to rehydrate. When you have diarrhea, a known cause of dehydration, you may also grab an electrolyte drink — all to help your body replenish and balance its fluids.

“Sometimes if you’re feeling sluggish, lethargic or kind of achy and tired, some of that could be due to an electrolyte imbalance,” Zumpano say. “A lot of times, if you drink something that has a little sodium or potassium, you almost immediately feel better.”

Helps regulate your blood pressure

The interplay between potassium and sodium can go a long way for improving blood pressure, aka hypertension. Consuming a lot of sodium increases your blood pressure, while consuming potassium can help decrease it.

In fact, the American Heart Association (AHA) says getting enough potassium can help prevent and even help treat high blood pressure.

“Potassium is so important when it comes to blood pressure,” Zumpano says. “For years, when it came to hypertension, we’d encourage patients to limit sodium through a low-salt diet. Now, we also recommend increasing potassium.”

Allows muscles to contract

Potassium helps transmit the nerve signals that your muscles need in order to be able to contract — basically, any movements that your muscles make, whether voluntary or involuntary. This includes from doing bicep curls to blinking and swallowing.

When you don’t have enough potassium, you can end up with achy, cramped muscles.

“You may not necessarily realize it or immediately relate it to low potassium levels,” Zumpano says, “but you’ll feel it in your muscles, like in some muscle cramping, weakness and fatigue.”

Helps your heart beat

Your heart is a muscle, too! Potassium helps it beat, prompting it to pump blood throughout your body.

“Potassium is critical for the heart to work, which makes it critical for heart health overall,” Zumpano says.

When your potassium level is out of whack, you can experience heart-related health issues, including heart palpitations, abnormal heart rhythm and even heart attack.

Lowers your risk of cardiovascular disease

In 2020, a review of studies on sodium and potassium found that higher potassium and lower sodium-to-potassium ratio were associated with a lower risk of cardiovascular disease — group of conditions that affect your heart and blood vessels.

Food sources of potassium

Potassium is an essential mineral, which means that although your body needs it, it can’t make it on its own. Instead, you have to get it through your diet or in supplement form. The good news is that it’s found in lots of fruits and vegetables, so the best way to get enough potassium is to eat the recommended seven to nine servings of fruits and veggies per day.

“Potassium is found in so many of the healthiest possible whole foods,” Zumpano says. “They’re all phenomenally nutrient-dense.” Potassium-rich foods include:

• Almonds.
• Avocado.
• Bananas.
• Cashews.
• Leafy greens.
• Flaxseeds.
• Lentils.
• Oranges.
• Potatoes.
• White beans.

“The darker the greens, the more potassium you're going to get,” Zumpano says. “To get enough potassium, try to include at least one source of leafy greens in your diet each day. And it’s good to vary the kinds of greens that you’re eating.”

The DASH diet, an eating plan designed to lower the risk of high blood pressure, includes lots of potassium-rich foods and other foods that can help prevent or stop hypertension.

How much potassium do I need?

If you’re eating a balanced diet, it’s not too difficult to get enough potassium. But the Dietary Guidelines for Americans names it is an “underconsumed nutrient,” in part because many Americans don’t eat the recommended amount of fruits and vegetables.

“If you're eating a variety of different fruits, vegetables, nuts and seeds, you're most likely going to get enough potassium,” Zumpano says, “but many people don’t get enough of it in their diets.”

So what is enough?

The U.S. Food and Drug Administration (FDA) recommends that 3,400 mg of potassium per day for men and 2,600 mg of potassium per day for women. But these guidelines don’t account for individual differences like sex assigned at birth, height, weight and overall health.

“The amount of potassium that each person needs will vary,” Zumpano says. “Certain medications, health conditions and lifestyle habits, like frequent exercise or sweating, can cause your body to need more potassium.”

If you’re concerned about how much potassium you need, ask a healthcare provider for personalized guidance.

Do you need a potassium supplement?

You probably don’t need a potassium supplement. In some instances, your healthcare provider may prescribe one, like if you’re taking diuretics or following a specific, medically recommended diet that limits the amount of potassium-rich foods you can eat (e.g. a protein-sparing modified diet).

Otherwise, you should be able to get plenty of potassium in foods like fruits and vegetables. “Most healthy people should be able to get plenty of potassium by eating a healthy diet,” Zumpano confirms.

Potassium-related health problems

Potassium is important enough to your bodily functions that if you get too much or too little of it, you can start to experience real health concerns. Let’s take a look at what can happen if your potassium levels are too high or too low.

Not enough potassium (hypokalemia)

There are lots of medical causes of low potassium, which is called hypokalemia. Eating disorders, inflammatory bowel diseases, excessive sweating, adrenal disorders and certain medications are just a few of the possible reasons your potassium levels might be too low.

Low potassium can also:

• Raise your blood pressure.
• Increase the risk of kidney stones.
• Pull calcium from your bones.

Over time, untreated hypokalemia can cause abnormal heart rhythms, muscle weakness and even paralysis.

Too much potassium (hyperkalemia)

Most people don’t need to worry about getting too much potassium. “It’s very unlikely for you to get too much through your diet,” Zumpano says, “and your body should be able to excrete any extra.”

But some conditions and lifestyle habits can lead to high potassium levels, which is known as hyperkalemia. The most common cause is chronic kidney disease (CKD).

Your kidneys are responsible for getting rid of extra potassium — but when your kidneys aren’t working right, then that extra potassium builds up in your body instead.

“When your kidneys aren’t able to get rid of what they should, that extra potassium accumulates in your bloodstream,” Zumpano says. “If your kidneys are already failing, adding extra nutrients like potassium causes your kidneys to have to work harder. It puts extra strain on an already strained organ.”

If you have CKD, it’s important to talk to your healthcare team to be sure your diet doesn’t put extra stress on your kidneys.

What happens when you focus on potassium

If you’re experiencing muscle fatigue or general aches and pains, you may want to keep an eye on your potassium intake and see if consuming more of it helps you feel better.

“Especially if you exercise a lot, those muscle cramps can be pretty significant if you're low in potassium,” Zumpano says. “Focusing on meeting your potassium needs may be an easy fix.”

She recommends aiming for one potassium-rich food per meal. If you’re already in the habit of eating a lot of leafy greens or other vegetables, you’re probably already doing this — and if not, homing in on potassium can be a first step to eating better overall.

“Focusing on a diet rich in potassium will provide not only this essential electrolyte but also a multitude of other healthy nutrients,” Zumpano says, “which leaves less room for junk food.”