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Functions | Recommended Intake | Potassium Deficiency | Potassium Toxicity | Major Food Sources | Tips for Increasing Your Potassium Intake

Potassium is a mineral and an electrolyte. Electrolytes are compounds that are able to conduct an electrical current.

Functions

Potassium's functions include helping to:

  • Regulate fluids and mineral balance in and out of body cells
  • Maintain your normal blood pressure
  • Transmit nerve impulses
  • Make your muscles contract

Recommended Intake

Most people should aim to get close to 5,000 milligrams (mg) of potassium per day.

Age Estimated Minimum Requirement of Potassium
(mg)
9-13 years4,500
> 13 years4,700

Potassium Deficiency

Severe potassium deficiency leads to a low potassium level in the blood, called hypokalemia. But a potassium deficiency is rare in healthy people. However, certain conditions can cause the body to lose significant amounts of potassium. Examples of these conditions include:

  • Excessive diarrhea or laxative use
  • Kidney problems
  • Use of certain blood pressure medicines
  • Continuous poor food intake (may occur due to alcoholism, anorexia nervosa, bulimia, very low calorie diets)

Signs of a severe potassium deficiency include the following:

If hypokalemia persists, it can lead to irregular heartbeat. This can dangerously decrease the heart's ability to pump blood.

In addition, people who are on high blood pressure medicine should ask their doctor about the need for a potassium supplement.

Potassium Toxicity

Potassium is rarely toxic because excess amounts are usually excreted in the urine. However, people with kidney problems may be unable to properly excrete potassium, allowing it to build up in the bloodstream (called hyperkalemia). Therefore, people with kidney problems need to closely monitor their potassium intake. Hyperkalemia can also lead to an irregular heartbeat. This can dangerously decrease the heart's ability to pump blood.

Major Food Sources

Potassium is found in many foods, especially fruits and vegetables. Less processed foods tend to have more potassium.

Here are some examples of foods that are high in potassium:

Food (amount)Serving Size Potassium Content
(mg)
White beans, canned1/2 cup595
Potato, baked with skin1 medium610
Lentils, cooked1/2 cup365
Clams, canned and drained3 ounces534
Yogurt, low fat, plain1 cup531
Lima beans, cooked1/2 cup484
Banana1 medium422
Dried apricots1/4 cup378
Cantaloupe1/4 medium368
Tuna, yellowfin, cooked 3 ounces484
Honeydew melon1/8 medium365
Winter squash½ cup 448
Cod, Pacific, cooked 3 ounces439
Spinach, cooked½ cup419
Milk, fat-free1 cup382
Kidney Beans, cooked½ cup358

Tips for Increasing Your Potassium Intake

To help increase your intake of potassium:

  • Eat legumes, such as black beans, lentils, and chickpeas, three times per week. Combine them with rice and vegetables and wrap in a warm tortilla.
  • Make garden salads with half green lettuce and half fresh spinach.
  • Eat fish as your entrée a few times per week.
  • Snack on dried fruits for a sweet fix.
  • Use avocado on sandwiches or bagels in place of mayonnaise or cream cheese.
  • Eat two brightly colored fruits and vegetables each day, like sweet potato, cantaloupe, honeydew melon, spinach, among others.

RESOURCES:

American Dietetic Association

http://www.eatright.org/

CANADIAN RESOURCES:

Canadian Council on Food and Nutrition

http://www.ccfn.ca/

Dietitians of Canada

http://www.dietitians.ca/

References

Chapter 8 sodium and potassium. Health.gov website. Available at: http://www.health.gov/dietaryguidelines/dga2005/document/html/chapter8.htm. Updated July 9, 2008. Accessed April 18, 2012.

Duyff RL. The American Dietetic Association's Complete Food & Nutrition Guide. 3rd ed. Hoboken, NJ: John Wiley and Sons, Inc; 2006.

Food sources of potassium. Health.gov website. Available at: http://www.health.gov/dietaryguidelines/dga2005/document/html/appendixb.htm. Updated July 9, 2008. Accessed April 18, 2012.

Hypertension. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/. Accessed February 15, 2008.

Hypokalemia. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/. Updated January 2, 2011. Accessed April 17, 2012.

Garrison R, Somer E. The Nutrition Desk Reference. New Canaan, CT: Keats Publishing; 1995.

Wardlaw G, Insel P. Perspectives in Nutrition. 2nd ed. St. Louis, MO: Mosby Year Book; 1993.

Whelton PK, He J, Cutler JA, et al. Effects of oral potassium on blood pressure. Meta-analysis of randomized controlled clinical trials. JAMA. 1997;277:1624–1632.

Last reviewed May 2012 by Peter J. Lucas, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.