Potassium is an essential mineral that is needed by all tissues in the body. It is sometimes referred to as an electrolyte because it carries a small electrical charge that activates various cell and nerve functions. Potassium is found naturally in many foods and as a supplement. Its main role in the body is to help maintain normal levels of fluid inside our cells. Sodium, its counterpart, maintains normal fluid levels outside of cells. Potassium also helps muscles to contract and supports normal blood pressure.
The U.S. Dietary Reference Intakes state that there is not enough evidence to establish a Recommended Dietary Allowance (RDA) for potassium. However, the National Academy of Medicine has established an Adequate Intake (AI) for potassium. 
- For women 14-18 years of age, the AI is 2,300 mg daily; for women 19+, 2,600 mg. For pregnant and lactating women, the AI ranges from 2,500-2,900 depending on age.
- For men 14-18 years of age, the AI is 3,000 mg; for men 19+, 3,400 mg.
It is estimated that the average daily intake of potassium in adults is about 2,320 mg for women and 3,016 mg for men.
Food Sources of Potassium
Many of the foods that you already eat contain potassium. The foods listed below are high in potassium. If you need to boost the amount of potassium in your diet, make healthy food choices by picking items below to add to your menu.
Many fresh fruits and vegetables are rich in potassium:
- Bananas, oranges, cantaloupe, honeydew, apricots, grapefruit (some dried fruits, such as prunes, raisins, and dates, are also high in potassium)
- Cooked spinach
- Cooked broccoli
- Sweet potatoes
- Leafy greens
Juice from potassium-rich fruit is also a good choice:
- Orange juice
- Tomato juice
- Prune juice
- Apricot juice
- Grapefruit juice
Some fish contain potassium:
Beans or legumes that are high in potassium include:
- Lima beans
- Pinto beans
- Kidney beans
Other foods that are rich in potassium include:
- Salt substitutes (read labels to check potassium levels)
- Meat and poultry
- Brown and wild rice
- Bran cereal
- Whole-wheat bread and pasta
How Much You Need
Women should get 2,600mg and men should get 3,400mg of potassium every day. Most Americans don’t meet that goal.
Your needs might be different if you have kidney disease. Some people with kidney disease should get less potassium than the guidelines. If your kidneys don’t work well, too much potassium could stay in your body, which can cause nerve and muscle problems. If you have kidney disease and your doctor hasn’t already told you what your potassium limit is, ask about it.
On the Label?
For a long time, potassium wasn’t listed on the Nutrition Facts food labels of packaged food items. But in May 2016, the Nutrition Facts rules were changed, and potassium will now be listed. Companies will need to update their food labels on or before January 2020. That should make it easier for you to track your potassium intake for better health.
Why You Need Potassium
For starters, it helps your blood pressure. It does this in two different ways:
- First, with the aid your kidneys, potassium helps remove extra sodium from your body through your urine. This is a good thing, because too much sodium can cause high blood pressure.
- Second, potassium helps the walls of your blood vessels to relax or loosen up. When they’re too tense or rigid, it can lead to high blood pressure, which can cause heart problems. Getting enough potassium is good for your heart.
You also need enough potassium for good muscle health — so that your muscles can flex or contract the way they should. And your nerves need potassium so that they can work well.
Signs of Deficiency and Toxicity
The kidneys work to maintain normal blood levels of potassium by flushing out excess amounts through urine. Potassium can also be lost through stool and sweat. At least 400-800 mg daily from food is needed because of normal daily losses. Any conditions that increase fluid losses beyond normal such as vomiting, diarrhea, and certain medications like diuretics can lead to a deficiency, called hypokalemia. Hypokalemia is most common in hospitalized patients who are taking medications that cause the body to excrete too much potassium. It is also seen in people with inflammatory bowel diseases (Crohn’s disease, ulcerative colitis) that may cause diarrhea and malabsorption of nutrients.
It is rare for a potassium deficiency to be caused by too low a food intake alone because it is found in so many foods; however an inadequate intake combined with heavy sweating, diuretic use, laxative abuse, or severe nausea and vomiting can quickly lead to hypokalemia. Another reason is a deficiency of magnesium, as the kidneys need magnesium to help reabsorb potassium and maintain normal levels in cells.
- Muscle cramps or weakness
- Muscle paralysis and irregular heart rate (with severe hypokalemia)
Too much potassium in the blood is called hyperkalemia. In healthy people the kidneys will efficiently remove extra potassium, mainly through the urine. However, certain situations can lead to hyperkalemia: advanced kidney disease, taking medications that hold onto potassium in the body (including NSAIDs), or people who have compromised kidneys who eat a high-potassium diet (more than 4,700 mg daily) or use potassium-based salt substitutes. Symptoms of hyperkalemia:
- Weakness, fatigue
- Nausea, vomiting
- Shortness of breath
- Chest pain
- Heart palpitations, irregular heart rate
Did You Know?
- The chemical symbol for potassium is “K,” not to be confused with vitamin K.
- Salt substitutes are sometimes made from potassium chloride, which replaces some or all of the sodium chloride in table salt. Although those on salt-restricted diets may benefit from its much lower sodium content, potassium salt has a bitter aftertaste when heated so it is not recommended for cooking. Check with your doctor before trying a potassium salt, because extra potassium can be dangerous for people who have trouble eliminating excess amounts or who are taking medications that can increase potassium levels in the bloodstream.
The contents of this website are for educational purposes and are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The Nutrition Source does not recommend or endorse any products.