Everything you need to know about potassium
A high potassium intake reduces the risk of overall mortality by 20 percent. It also decreases the risk of stroke, lowers blood pressure, protects against loss of muscle mass, preserves bone mineral density, and reduces the formation of kidney stones.
The primary functions of potassium in the body include regulating fluid balance and controlling the electrical activity of the heart and other muscles.
This MNT Knowledge Center article provides an in-depth look at recommended intake of potassium, its possible health benefits, reliable sources of potassium, the effects of consuming too much or too little potassium, and any potential health risks of consuming potassium.
- Adults should be consuming 4,700 milligrams (mg) of potassium a day. However, fewer than two percent of people in the U.S. consume enough potassium.
- Potassium supports blood pressure, cardiovascular health, bone strength, and muscle strength.
- Beet greens, white beans, soy beans, and lima beans are the foods highest in potassium.
- Potassium deficiency can lead to fatigue, weakness, and constipation. It can escalate to paralysis, respiratory failure, and painful gut obstructions.
- Hyperkalemia means that there is too much potassium in the blood, and this can also impact health.
- Potassium is available in supplements, but dietary sources are most healthful.
Potassium is a crucial nutrient, and a very small percent of people in the U.S. consume enough.
The Adequate Intake recommendation for potassium is 4,700 milligrams (mg) per day for adults. Most adults do not meet this recommendation.
The National Health and Nutrition Examination Survey (NHANES) also reported that less than two percent of people in the U.S. meet the daily 4,700-mg potassium requirement. Women consume less potassium than men on average.
The World Health Organization (WHO) recommend an intake of 3,510 mg per day and agree that most of the global population is not meeting this recommendation.
Potassium supplements are available. However, it is best to obtain any vitamin or mineral through food. It is not individual vitamins or minerals that make certain foods important for healthful living, but the combined efforts of a range of nutrients.
Potassium carries proven health benefits.
It is an electrolyte that counteracts the effects of sodium, helping to maintain consistent blood pressure. Potassium is also important for maintaining the balance of acids and bases in the body. Bases are alkalis that have not yet dissolved in water.
Blood pressure and cardiovascular health
Low potassium intake has repeatedly been linked with high blood pressure and cardiovascular disease. Maintaining a low sodium intake is essential to lowering blood pressure, but ensuring a good intake of potassium may be just as important.
An increase in potassium intake along with a decrease in sodium is crucial to reducing the risk of cardiovascular disease.
Bone and muscle maintenance
Potassium-rich foods maintain an alkaline environment in the body, unlike in acidosis. Metabolic acidosis is triggered by a diet full of acidifying foods like meat, dairy products, and processed cereal grains. Acidosis is a common outcome of the typically acidic Western diet.
Acidosis can cause nitrogen excretion, loss in bone mineral density, and muscle wasting. A diet high in potassium can help preserve muscle mass in older people, as well as during conditions that tend to lead to muscle wasting, such as diabetic ketosis. However, a sufficient potassium intake can help prevent this.
One study found that participants that took in 5,266 milligrams of potassium per day maintained an average of 3.6 more pounds of lean tissue mass than those with a potassium intake 50 percent lower. Some studies also show an increase in bone density with high potassium intake.
Foods high in potassium
White beans are among the most potassium-rich foods, as are many other types of bean.
Potassium is found in many whole, unprocessed foods.
Some of the best sources of potassium are fresh leafy greens, avocados, tomatoes, potatoes, and beans. Processing greatly reduces the amount of dietary potassium. A diet high in processed foods is probably low in potassium.
Many processed foods are also high in sodium. As sodium consumption rises, increased potassium is needed to cancel out the effect of sodium on blood pressure.
Here is a table showing the nutritional benefit provided by one cup of the most potassium-rich foods.
|Food type (1 cup)||Amount of potassium provided in milligrams (mg)|
|Cooked, boiled, or drained beet greens, without salt||1,309|
|Canned white beans||1,189|
|Cooked, boiled, or drained soy beans, without salt||970|
|Cooked, boiled, or drained lima beans, without salt||969|
|Baked sweet potato||950|
|Cooked, boiled, or drained mushrooms, without salt||555|
|Red, ripe, raw tomatoes||427|
|Raw cantaloupe melon||417|
A good way to reduce the harmful effects of high-sodium meals is to eat a high-potassium fruit or vegetable with each meal.
There are many more sources of potassium outside of this list. Be sure to check the potassium content of any preferred foods using the United States Department of Agriculture (USDA) National Nutrient Database.
Fatigue is a symptom of potassium deficiency.
Potassium deficiency can cause a range of symptoms and health problems. It is also known as hypokalemia.
A normal potassium level is defined as between 3.5 and 5.0 millimoles per liter (mmol/L).
Hypokalemia is diagnosed when potassium levels fall below 3.5 mmol/L. Mild potassium deficiency will generally not present with symptoms. A potassium level lower than 2.5 mmol/L is considered extremely deficient, and symptoms will become more severe as levels reduce.
Symptoms of low potassium levels include:
- malaise and fatigue
- weakness and muscle pain all over the body
Extremely low potassium levels can cause:
- severe muscle weakness and paralysis
- respiratory failure
- painful obstructions in the gut
- tingling, crawling, numb, or itchy sensations main felt in the hands, feet, legs, or arms
- intermittent muscle spasms
Low potassium can be diagnosed using simple blood tests and treated by alterations to the diet, including supplements. Having regular medicals and health screenings will also help a person track their potassium levels and avoid any potential shortfalls.
Potassium can also cause health problems when a person consumes more than the 4,700 mg recommended Adequate Intake.
Individuals with good kidney function can efficiently rid the body of excess amounts of potassium in the urine. This process normally has no adverse side effects.
There have been a small number of reports that potassium toxicity is associated with an extremely high intake of potassium supplements. No food-related potassium toxicity has ever been reported.
Consuming too much potassium can be harmful to people whose kidneys are not fully functional. Excessive potassium consumption can lead to hyperkalemia, in which the kidneys cannot remove enough potassium from the body. This can be dangerous if the condition escalates quickly.
Potassium levels between 5.1 and 6.0 mmol/L are considered high and warrant monitoring and management. Levels higher than 6.0 mmol/L are dangerous.
Hyperkalemia will mostly be either symptomless or present very few symptoms. However, when symptoms do present, they are similar to those that occur in hypokalemia.
Severe or sudden hyperkalemia can cause heart palpitations, shortness of breath, and chest pain. At this stage, hyperkalemia can become a life-threatening condition that requires immediate medical attention.
Reducing potassium intake
Hyperkalemia is treated by reducing the intake of potassium.
Potassium and sodium are part of a constant balancing act within the body. Maintaining this balance is vital to the smooth function of bodily systems.
If hyperkalemia is suspected, it is best to avoid high-potassium foods, such as the ones listed above. Salt substitutes, herbal remedies, or supplements should also not be consumed. These can all boost potassium levels rather than balance them.
High potassium levels have been linked to two cases of cardiac arrest. If the kidneys are unable to remove excess potassium from the blood, the effects of potassium on the heart could be fatal.
Potassium is vital to bodily function but does not hold the answers to healthful living on its own. Overall eating patterns and dietary balance are most important in bolstering health and keeping disease at bay.