Healthy people seldom have problems getting enough potassium if they eat a varied diet. But for those who are sick, with vomiting and diarrhea, potassium losses can become severe. People with anorexia nervosa and bulimia, whose diets are poor and whose bodies are nutrient depleted from vomiting and laxative use, are also at risk for potassium deficiency, with potentially life-threatening effects.
Individuals taking a potassium-depleting diuretic medication may need to eat more high-potassium foods. While the doctor may routinely recommend a banana a day for potassium, the good news is there are many excellent food sources found in fruits and vegetables. Leafy greens and starchy vegetables like sweet potatoes, beans, nuts, and dairy foods are rich in potassium. Fresh foods with limited processing are the best sources of potassium.
Potassium’s roles in the body include:
- maintains fluid and electrolyte balance
- helps transmit nerve impulses
- helps regulate blood pressure and reduces the risk of stroke
- helps maintain a regular heartbeat
- helps prevent muscle cramps
Eating adequate amounts of both calcium and potassium while consuming a low-sodium diet may prevent bone fractures and osteoporosis. A potassium-rich diet may also lower the risk of some types of kidney stones and hypertension. In addition, a diet low in potassium yet high in sodium and protein increases the amount of calcium excreted in the urine.
How Much Potassium Is Needed?
The 2020 Dietary Guidelines for Americans recommends consuming the following amounts of potassium daily:
Amount of Potassium Needed Daily
|Mg of Potassium||Age Group|
|4,700||Adults and adolescents|
|4,500||Children 9-13 years old|
|3,800||Children 4-8 years old|
|3,000||Children 1-3 years old|
Most Americans get only half of this daily recommendation.
Certain population groups tend to be more salt-sensitive. The following groups should aim to meet the potassium recommendation of 4,700 mg per day with food while consuming no more than 1,500 mg of sodium per day:
- individuals with hypertension or high blood pressure
- African Americans
- middle-aged and older adults
In general, African Americans have a high prevalence of elevated blood pressure and salt sensitivity. They may especially benefit from eating more potassium-rich foods.
Potassium supplements should not be used unless a doctor recommends them. However, they are sold over-the-counter and in many health food stores without a warning label.
Sources of Potassium
A key recommendation of the 2020 Dietary Guidelines for Americans is to consume potassium-rich foods, such as fresh, whole fruits and vegetables, while consuming foods with little salt. Most processed foods contain less potassium and more sodium than fresh foods. Two cups of fruit and 2½ cups of vegetables should be consumed daily for a 2,000-calorie intake.
Potassium should come from food sources, not supplements. The best sources are fresh foods with limited processing, especially leafy green vegetables, root vegetables, legumes (dry beans), and fruits. Although meat, milk, and cereal products contain potassium, the form of potassium in these foods is not as readily available for absorption by the body. The following table contains fruits, vegetables, and legumes that are excellent sources of potassium:
Potassium Sources, Smaller Portion
|Beet greens, cooked, ½ cup||655||20|
|Lima beans, cooked, ½ cup||485||105|
|Swiss chard, cooked, ½ cup||481||18|
|Potato, baked, with skin, ½ medium||463||81|
|Yam, cooked, ½ cup||456||79|
|Acorn squash, cooked, ½ cup||448||58|
|Spinach, cooked, ½ cup||420||21|
|Carrot juice, 100%, ½ cup||345||47|
|Plantains, cooked, ½ cup||332||108|
|Butternut squash, cooked, ½ cup||291||41|
|Sweet potato, cooked, ½ cup||286||95|
|Broccoli raab, cooked, ½ cup||275||20|
|Mushrooms, portabella, cooked, ½ cup||265||18|
|Stewed tomatoes, canned, ½ cup||264||33|
|Vegetable juice, 100%, ½ cup||259||24|
|White beans, cooked, ¼ cup||251||62|
|Durian, ½ cup||530||179|
|Jackfruit, ½ cup||370||79|
|Prune juice, 100%, ½ cup||354||91|
|Kiwifruit, ½ cup||281||55|
|Pomegranate juice, 100%, ½ cup||267||67|
|Orange juice, 100%, ½ cup||248||56|
|Melon, cantaloupe, ½ cup||237||30|
|Banana, ½ medium||226||56|
|Grapefruit, ½ fruit||208||65|
|Apricots, ½ cup||201||37|
|Tangerine (tangelo), ½ cup||162||52|
|DAIRY AND FORTIFIED SOY ALTERNATIVES|
|Yogurt, plain, nonfat, 4 ounces||313||69|
|Yogurt, plain, low fat, 4 ounces||287||77|
|Milk, fat free (skim), ½ cup||191||42|
|Milk, low fat (1%), ½ cup||183||51|
|Yogurt, Greek, plain, nonfat, 4 ounces||160||67|
|Yogurt, Greek, plain, low fat, 4 ounces||160||83|
|Soy beverage (soy milk), unsweetened, ½ cup||146||40|
|Clams, 1 ounce||178||42|
|Tempeh, ¼ cup||171||80|
|Tofu, raw, firm, prepared with calcium sulfate, ¼ cup||150||91|
|Pistachio nuts, ½ ounce||143||81|
|Salmon (various), 1 ounce||~140-270||~40-60|
|Rainbow trout, freshwater, 1 ounce||128||47|
|Tilapia, 1 ounce||108||36|
|Pork, 1 ounce||101||57|
|Game meats (various), 1 ounce||~95-115||~40-60|
|Taken from: U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, 2019. fdc.nal.usda.gov.|
Bananas, just one of many potassium-rich foods, are often recommended by healthcare professionals because they are readily available, easy to chew, and taste sweet, which almost everyone likes.
High Blood Pressure
Potassium, an essential mineral, works with sodium, calcium, and magnesium to protect against high blood pressure or hypertension. Conversely, a low potassium diet raises blood pressure. Understanding the relationship between potassium and sodium is important for managing hypertension because both have opposite effects in the body. Both nutrients play vital roles in maintaining physiological balance and have been linked to the risk of chronic diseases, especially cardiovascular disease. Increased sodium intake raises blood pressure, while increased potassium intake can help relax blood vessels and excrete sodium while decreasing blood pressure. A potassium-rich diet blunts the effects of salt on blood pressure, may reduce the risk of developing kidney stones, and decreases bone loss associated with aging. Fruits and vegetables rich in potassium appear to reduce the risk of stroke, also.
Doctors often prescribe diuretics to help decrease blood pressure. Some of these medications cause a loss of potassium since the potassium accompanies excess water that the body excretes to lower the blood pressure. Patients are advised to eat foods rich in potassium to make up for these losses. Lower sodium or salt intake is usually recommended, also.
Many salt substitutes are made of potassium chloride and contain no sodium. Salt substitutes are often recommended for people on a sodium-restricted diet. Check with a doctor before using salt substitutes. Salt-free herb blends, as well as lemon and lime juice, are excellent alternatives for flavoring food.
Excess of Potassium
Usually, an overdose of potassium is not life-threatening since excess potassium triggers a vomiting reflex in the stomach. Babies and people with weak hearts may not be able to withstand this trauma. Consuming too much potassium can be harmful to people with kidney problems because they cannot get rid of the excess.
There is no chronic disease associated with too much potassium. When excess potassium is present in the blood, the cause is usually a health problem such as kidney failure, uncontrolled diabetes, or the use of certain drugs. Excess potassium can trigger a heart attack and result in death.
A potassium deficiency is unlikely in healthy people unless the diet primarily consists of highly processed foods. A deficiency is usually caused by losing excessive amounts of potassium rather than not getting enough in the diet.
The earliest symptoms of a deficiency are tiredness, muscle weakness, and heart muscle irritability, followed by paralysis and confusion. The following conditions can cause a potassium deficiency:
- dehydration (includes excessive sweating)
- prolonged diarrhea or vomiting (includes anorexia nervosa and bulimia)
- diabetic acidosis
- regular use of certain drugs such as diuretics, strong laxatives, and steroids
- certain chronic diseases like adrenal gland disorders, nephritis, and acute leukemia
Note: Low potassium symptoms can last for days.
- Aaron KJ, Sanders PW. Role of dietary salt and potassium intake in cardiovascular health and disease: a review of the evidence. In Mayo Clinic Proceedings 2013 Sep 1 (Vol. 88, No. 9, pp. 987-995). Elsevier.
- Duyff, Roberta Larson. American Dietetic Association Complete Food and Nutrition Guide, 2nd Edition. 2002.
- Newberry SJ, Chung M, Anderson CA, Chen C, Fu Z, Tang A, Zhao N, Booth M, Marks J, Hollands S, Motala A. Sodium and Potassium Intake: Effects on Chronic Disease Outcomes and Risks. Rockville (MD): Agency for Healthcare Research and Quality (US); 2018 Jun. Report No.: 18-EHC009-EF.
- Sizer, Frances and Eleanor Whitney. Nutrition Concepts and Controversies, Ninth Edition. 2003.
- U.S. Department of Agriculture, Agricultural Research Service. FoodData Central, 2019. fdc.nal.usda.gov.
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. Available at DietaryGuidelines.gov.
- Whitney, Ellie and Sharon Rady Rolfes. Understanding Nutrition, Tenth Edition. 2005.
Originally published 06/05