The Health Benefits of Potassium

Benefits, Side Effects, Dosage, and Interactions

Potassium is an essential mineral and electrolyte that plays a critical role in many functions of the body, including regulating your heart beat and blood pressure, proper nerve conduction, protein synthesis, glycogen (storage form of glucose) synthesis, and muscle contraction. It is one of the major minerals responsible for maintaining osmotic pressure in the intra and extracellular environments.

Potassium is found naturally in most fruits, vegetables, legumes, and seeds. In healthy individuals with normal kidney function, abnormally low or high blood levels of potassium are rare. 

Health benefits of potassium
Verywell / JR Bee 

Health Benefits

Some studies suggest that higher intakes of potassium may reduce the risk of certain diseases including, stroke, osteoporosis, and kidney stones. Additionally, researchers have found an inverse relationship between potassium intake and blood pressure in those people with hypertension (high blood pressure) and low levels of potassium. People who consume a larger variety of fruits and vegetables seem to benefit the most.

Reduction of Stroke

According to the Center of Disease Control, stroke is the fifth leading cause of death in the United States and is a major cause of serious disability in adults. You can lower your chances or prevent the risk of stroke by taking various actions.

Results from a clinical control trials suggest that increased intake of potassium is associated with a decreased risk of stroke.

Increased Bone Mineral Density

The modern Western diet tends to be relatively low in sources of alkali (fruit and vegetables) and high in sources of acid (fish, meats, and cheeses). When the pH balance is off, the body can take alkaline calcium salts from bone in order to neutralize the pH. Some scientists believe that an increased consumption of potassium rich fruit and vegetables or potassium supplementation reduces the net acid content of the diet and may preserve calcium in bones.

The research on this subject is mixed. A study conducted in the American Journal of Clinical Nutrition measured the effects of potassium citrate supplementation and increased fruit and vegetable consumption in 276 postmenopausal women. It found that after two years of potassium citrate supplementation, bone turnover was not reduced and there was no increase in bone mineral density.

In contrast, another study published in the journal Nutrients found that potassium citrate supplementation improved the beneficial effects of calcium and vitamin D in osteopenic women who had a potassium deficit. This study suggests that potassium’s ability to increase bone mineral density may also rely on the intake of calcium and vitamin D, both of which are nutrients important for bone health. More research is needed to determine its effects.

Kidney Stones

Abnormally high urinary calcium (hypercalciuria) increases the risk of developing kidney stones. Diets that are high in protein and low in potassium may contribute to increasing stone formation. Increasing potassium intake whether by increasing fruits and vegetables or increasing supplementation may decrease urinary calcium, hence, reducing the risk of kidney stones. In a study published in the Clinical Journal of American Society of Nephrology, researchers examined the relationship between protein and potassium intake on kidney stones.

They found that higher dietary potassium was associated with a statistically significant and large reduction in kidney stone risk in all cohorts. They also found that the type of protein consumed may also affect kidney stone risk. They suggest, “diets rich in fruits and vegetables as well as diets with a relative abundance of fruits and vegetables compared with animal protein may represent effective interventions to prevent kidney stone formation.”

Treatment of Hypertension

High blood pressure can make the heart work too hard and increases the risk of heart disease as well as other health conditions such as stroke, congestive heart failure, kidney disease, and blindness. In an older but very memorable clinical trial, Dietary Approaches to Reduce Hypertension (DASH) published in the New England Journal of Medicine, researchers determined that a diet rich in fruits, vegetables, and low-fat dairy foods, and with reduced saturated and total fat can substantially lower blood pressure.

Compared to a control diet (offering 3.5 servings a day of fruits and vegetables and 1,700 milligrams per day of potassium), eating a diet which included 8.5 servings per day of fruit and vegetables and 4,100 mg per day of potassium lowered blood pressure. Recent studies have also found that increasing intake of fruits and vegetables (foods naturally rich in potassium) can reduce blood pressure. 

Prevention of Muscle Cramping

Extensive exercise does require replacement of electrolytes, both potassium and sodium, because they are lost through sweat. However, for the prevention of muscle cramping, adequate amounts of potassium and sodium before, during, and after exercise seem to be most important.

Possible Side Effects

If you are increasing your intake of fruits and vegetables, you will be increasing your intake of potassium as well as fiber. When increasing fiber, it is important to increase slowly and gradually to prevent gas and bloating. In addition, make sure to drink adequate amounts of fluids. Neglecting to hydrate properly can result in constipation and in severe cases intestinal blockage.

 The most common side effects of potassium supplements include:

  • Nausea
  • Vomiting
  • Abdominal discomfort
  • Diarrhea
  • Hyperkalemia (too much potassium in the blood)

To prevent side effects, make sure to take your supplements as prescribed, preferably with meals or liquid, to reduce gastrointestinal effects.

If you are taking potassium supplements, your blood will have to be monitored as elevated potassium in the blood can be very dangerous.

Dosage and Preparation

In March of 2019, the National Academies of Sciences, Engineering, and Medicine (NASEM) determined that there was inadequate evidence to determine the Recommended Dietary Allowance (RDA) for Americans for potassium and, therefore, determined that the adequate intake or AI (intake at this level is assumed to ensure nutritional adequacy) is 3,400 mg for males years 19 and older and 2,300 mg for women 19 and older.

Variations of AI will depend on gender, age, and pregnancy and lactation. This is a change from the previous recommendations which encouraged adults to consume 4,700 mg of potassium every day. The change likely took place because most healthy Americans consume around 2,500 mg per day of potassium. It should be noted that the new AIs do not apply to individuals with impaired potassium excretion because of medical conditions (for instance, kidney disease) or the use of medications that impair potassium excretion.

Storage and Preparation

Store fresh fruits and vegetables using best practices for maximizing their freshness. This will differ depending on the fruit or vegetable. Some should be refrigerated, while others, such as tomatoes, should be left at room temperature.

Avoid using very high heat or boiling your fruits and vegetables to preserve vitamin content. If you like, you can eat certain fruits and vegetables raw—otherwise, sauté them on medium heat with a small amount of fat, such as olive oil, or you can try steaming them.

If you are taking a potassium supplement, keep them in a cool, dry place away from heat and moisture. Prepare and take supplements as directed by your doctor/medical team.

Contraindications

Individuals with abnormal kidney function and those on potassium-sparing medications or ACE inhibitors, which are typically used for treating high blood pressure, may need to monitor their intake of potassium and probably should not be on a potassium supplement. If for some reason, your doctor has recommended this, your blood will be monitored closely to prevent hyperkalemia (high blood potassium).

If you are taking certain medications, you should avoid taking potassium supplements. These types of medications include spironolactone, triamterene, amiloride, captopril, enalapril, fosinopril, indomethacin, ibuprofen, ketorolac, trimethoprim-sulfamethoxazole, pentamidine, heparin, digitalis, β-blockers, α-blockers, losartan, valsartan, irbesartan, and candesartan.

Whenever you have a question about the interaction of supplementation with an existing medication or supplement, always consult your physician.

What to Look For

One of the best ways to increase potassium intake in your diet is to increase your consumption of fruits and vegetables. By doing so, you’ll likely reduce your intake of processed foods, which will reduce your intake of sodium. A diet low in sodium and high in potassium is a recipe for a healthy heart.

If you have trouble adding fresh produce to your diet due to cost of spoilage, consider adding frozen fruits and vegetables. These types of fruits and vegetables are frozen at peak freshness, enhancing their nutrition profile by making vitamins and minerals more readily available.

How to Meet Your Needs

The most optimal way to achieve your potassium needs is to eat a variety of whole foods including fruits like avocados, oranges, bananas, vegetables (such as sweet potatoes, squash, and dried beans), low-fat milk, and certain sources of protein like salmon and chicken. It is estimated that the body absorbs about 85 to 90 percent of dietary potassium.

The forms of potassium in fruits and vegetables include potassium phosphate, sulfate, citrate, and others—not potassium chloride, which is found in some potassium salt supplements.

In 2016, the Food and Drug Administration (FDA) announced that potassium must become a mandatory part of the nutrition facts label. “For potassium, we concluded that potassium is a nutrient of public health significance for the general U.S. population and its declaration is necessary to assist consumers in maintaining healthy dietary practices,” states the FDA.

Supplementing with Potassium

Supplementing with potassium is confusing and controversial. While it is always beneficial to receive your potassium intake from foods, some people continue to fall short of the adequate intake of potassium. If you are unsure as to whether you need to supplement with potassium, seek professional guidance—your physician or dietitian can help.

Potassium supplements are available as liquid, tablets, capsules and come in the forms of potassium gluconate, aspartate, citrate, or chloride. The amount you should take and the type should be determined by a medical professional.

Most over-the-counter potassium supplements as well as multivitamin-mineral supplements provide no more than around 99 mg of potassium per serving (which is a very small percentage of the recommended intake). In the past, the FDA ruled that some oral drug products that contain potassium chloride and provide more than 99 mg potassium are not safe because they have been associated with small-bowel lesions.

They have required some potassium salts which exceed 99 mg to be labeled with a warning of small-bowel lesions. However, they have not issued a ruling about whether dietary supplements containing more than 99 mg should carry a warning label. They report, “we have not established any limits on potency of recommended uses for dietary supplements that contain potassium salts.” Many salt substitutes contain potassium chloride as a replacement for some or all of the sodium chloride in salt.

The potassium content of these products varies widely, and labels should be read carefully, especially for those people who have an increased risk of hyperkalemia. Keep in mind that the percentage of absorption of supplements with vary based on the type of potassium derivative. For more information on potassium supplements, the National Institutes of Health has provided more information with their Dietary Supplement Label Database.

If your potassium levels are inadequate due to a medical condition, your physician will likely write you a prescription for potassium. If this occurs, she or he will monitor your blood levels closely to make sure they do not exceed the limit.

Foods High in Potassium:

According to the USDA nutrition database, the following are foods high in potassium. See below for a list of these foods followed by the amount of potassium each contains.

  • Acorn squash (1 cup cooked without salt): 896 milligrams
  • Apple (1 medium with skin): 195 milligrams
  • Artichokes (1 cup hearts cooked): 480 milligrams
  • Avocado (1/4 of the whole): 172 milligrams
  • Banana (1 medium): 430 milligrams
  • Beets (1 cup raw): 442 milligrams
  • Broccoli (1 cup chopped and cooked): 457 milligrams
  • Baby Brussels sprouts (13 pieces): 315 milligrams
  • Beans (1/2 cup dried—amounts vary based on variety): 1,813 milligrams
  • Cantaloupe (1 cup cubes): 427 milligrams
  • Carrots (1 cup chopped): 410 milligrams
  • Cherries (1 cup without pits): 342 milligrams
  • Milk (1 cup low-fat): 350-380 milligrams
  • Mushrooms (1 cup whole): 305 milligrams
  • Orange (1 small): 238 milligrams
  • Peas (1 cup raw): 354 milligrams
  • Peppers (1 cup chopped): 314 milligrams
  • Parsley (1 cup chopped): 332 milligrams
  • Potato (1 medium baked with skin): 930 milligrams
  • Quinoa (1 cup cooked): 318 milligrams
  • Salmon (6 ounces): 730 milligrams
  • Spinach (1 cup cooked): 839 milligrams
  • Sweet potato (1 cup baked ): 664 milligrams
  • Tomatoes (1 cup chopped): 430 milligrams
  • Yogurt (1 cup low-fat): 563 milligrams
  • Watermelon (1 cup diced): 170 milligrams

Processed Foods

Some processed and packaged foods also contain added potassium salts or naturally occurring potassium (such as dried beans and whole grains). If you must monitor your potassium intake, be mindful of labels. Most ingredient labels will list “potassium chloride” as an additive. This is typically found in foods such as cereal, snack foods, frozen foods, processed meat, soups, sauces, snacks, and meal bars.

You may also find added potassium in products such as Emergen C. Foods that contain at least 350 milligrams per serving are permitted by the FDA to state, “Diets containing foods that are good sources of potassium and low in sodium may reduce the risk of high blood pressure and stroke.”

Common Questions

When do I need to supplement with potassium?

It's not recommended for your overall health to have deficient potassium levels. However, most diets that are insufficient in potassium usually do not impair blood levels of potassium. In this case, it is encouraged for people to increase their intake of potassium rich foods, such as fruits and vegetables. For those people with increased risk of developing hypokalemia (low levels of potassium in the blood), a potassium supplement may be necessary.

People who are most at risk of developing this condition include those people with inflammatory bowel disease, those taking potassium wasting diuretics, those people that drink alcohol excessively, severe vomiting or diarrhea, overuse or abuse of laxatives, anorexia nervosa or bulimia, or congestive heart failure. Before beginning any type of supplement, make sure you clear it with your healthcare professional. Excessive intake of potassium can be hazardous to your health.

Can eating too much licorice cause hypokalemia?

There has been some information that suggests habitual consumption of large amounts of black licorice has resulted in low levels of potassium in the blood. The actual dose has not been determined.

Does cooking foods change the potassium content?

Boiling vegetables for long periods of time can reduce the potassium content by leaching it into the water. If you are trying to preserve vitamins and minerals, one of the best cooking methods is steaming or lightly sautéing over medium heat with a small amount of fat.

A Word From Verywell

Potassium is an abundant mineral that is important for health and well-being. Established studies have shown the benefits of increased potassium intake on the reduction of blood pressure, heart disease, stroke, and kidney stones. The best way to achieve your potassium needs is to eat a diet rich in fruits, vegetables, legumes, whole grains, and certain protein sources like salmon. Anyone taking potassium supplements should be monitored and guided by a health professional. Careful attention to processed food labels is warranted, especially for those people with kidney disease who are at increased risk of developing hyperkalemia.

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Article Sources

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  • Granchi, D, et. al. Potassium Citrate Supplementation Decreases the Biochemical Markers of Bone Loss in a Group of Osteopenic Women: The Results of a Randomized, Double-Blind, Placebo-Controlled Pilot Study. Nutrients. 2018 Sep 12;10(9). pii: E1293. DOI: 10.3390/nu10091293.

  • Linus Pauling Institute. Potassium.

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