by Karen Schroeder Kassel, MS, RD, MEd
Potassium is a mineral and an electrolyte. Electrolytes are compounds that are able to conduct an electrical current.
Potassium's functions include helping to:
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 years | 4,500 |
| > 13 years | 4,700 |
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:
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 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.
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, canned | 1/2 cup | 595 |
| Potato, baked with skin | 1 medium | 610 |
| Lentils, cooked | 1/2 cup | 365 |
| Clams, canned and drained | 3 ounces | 534 |
| Yogurt, low fat, plain | 1 cup | 531 |
| Lima beans, cooked | 1/2 cup | 484 |
| Banana | 1 medium | 422 |
| Dried apricots | 1/4 cup | 378 |
| Cantaloupe | 1/4 medium | 368 |
| Tuna, yellowfin, cooked | 3 ounces | 484 |
| Honeydew melon | 1/8 medium | 365 |
| Winter squash | ½ cup | 448 |
| Cod, Pacific, cooked | 3 ounces | 439 |
| Spinach, cooked | ½ cup | 419 |
| Milk, fat-free | 1 cup | 382 |
| Kidney Beans, cooked | ½ cup | 358 |
To help increase your intake of potassium:
American Dietetic Association
http://www.eatright.org/
Health.gov
http://www.health.gov/
Canadian Council on Food and Nutrition
http://www.ccfn.ca/
Dietitians of Canada
http://www.dietitians.ca/
Chapter 8 sodium and potassium. Health.gov website. Available at: http://www.health..... 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..... 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
Last Updated: 5/7/2012