Potassium is a soft, silvery-white metal found naturally in the earth, and is extremely important for the function of certain processes in the human body. It’s also an electrolyte – a substance necessary for the conduction of electrical signals throughout the body.
“She’s in the ‘three electrolytes’ gang of sodium and chloride,” says Cathy Lyman, RD, personal trainer, nutrition therapist, speaker, writer, and breast cancer survivor in Chicago. “It’s an integral part of every cell,” and essential for cell growth and nerve signaling.
Potassium is part of many foods and is “very soluble in water, so it is easy to absorb and can be used easily,” Lyman says.
What does potassium do?
Potassium is “very important in generating muscle contractions and regulating the heartbeat,” Lyman says, and plays a large role in energy metabolism. It helps the body build proteins from amino acids and metabolize carbohydrates for energy. Potassium helps your body convert glucose (sugar) into glycogen, which is then stored in your liver, so you have fuel for walking, running, or doing whatever else you want to do.
“Potassium is also involved in a process called the sodium-potassium exchange that occurs across cell membranes,” Lyman says. “This is what generates the electrical potential that helps all the nerve impulses in the body.” As such, “potassium is related to nerves, heart rate, and muscle contraction.”
In fact, every movement your body makes and any thoughts you have are made possible thanks to potassium, which helps cells communicate with each other.
In particular, eating adequate levels of potassium is critical to keeping your heart working properly. The heart is basically one large muscle, so adequate potassium levels are important to keep the heart working properly.
Sierra Holly, MD, a registered dietitian at The Ohio State University Wexner Medical Center in Columbus, adds that potassium helps maintain a regular heartbeat. “Both too little potassium and too much potassium can cause an arrhythmia, or arrhythmia.”
Potassium also has many other important functions, including:
- Helping cells maintain the proper osmotic pressure, or maintain the correct fluid balance to function optimally.
- Help maintain the body’s pH balance. Potassium is an essential element, meaning it is alkaline in nature, which helps balance excess acidity. Excess acidity can lead to cell death, so again, staying within the correct pH zone is key to maintaining elective function.
- Helping maintain proper pancreatic secretion of insulin, a key component of metabolic function that also helps regulate blood sugar levels.
- Helping offset the effect of sodium on blood pressure. Holly notes that “studies examining the effect of potassium intake on blood pressure have reported improvement in systolic and diastolic blood pressure for participants with increased potassium intake.” “Because high blood pressure is a risk factor for cardiovascular disease, potassium may also help prevent CVD.”
Essentially, potassium helps the body maintain the delicate balance that makes life possible. “These electrical pulses are finely tuned, and they balance out on a very thin wire,” Lyman says. “With the sodium-potassium exchange, it’s more like a finely tuned dance. One step — and that bump could be from diarrhea or vomiting or a drug that changes the potassium level in the body — and that changes everything.”
How much potassium should I consume each day?
The National Institutes of Health Office of Dietary Supplements reports that adults age 19 or older should consume 4,700 milligrams of potassium per day. (For reference, one medium banana contains about 400 mg of potassium.)
Breastfeeding women should aim for 5,100 mg per day, while children under 13 years old need as little as 400 mg for the first six months up to 4,500 mg per day between ages 9 and 13.
What foods are rich in potassium?
Bananas are often listed as the food of choice for people looking to add potassium to their diet, but they are not the only food with significant levels of this vital nutrient.
“The good thing about potassium is that it’s found in a wide variety of foods,” Lyman says.
Good sources of potassium
Whole foods such as fruits and vegetables offer the highest potassium levels. Good sources include the following foods, which contain moderate amounts of potassium, as reported by the USDA:
- banana. One medium banana contains 422 mg of potassium.
- orange; One small orange contains about 175 mg.
- grapefruit. Half of a pink grapefruit contains about 165 mg.
- Watermelon, including cantaloupe (417 mg per cup), aphid (388 mg per cup) and watermelon (170 mg per cup).
- apricot; 427 mg per cup.
- kiwi. A whole kiwi fruit contains 215 mg of potassium.
- Dried fruits such as prunes, raisins and dates. One peach contains 70 mg potassium. One small packet (1.5 ounces) of raisins contains 322 mg of potassium. One Medjool date contains 170 mg of potassium.
- avocado. One whole avocado contains 975 mg of potassium.
- sweet potato. One sweet potato (about 5 inches) contains about 440 mg of potassium.
- white potatoes One large potato (about 3 to 4 inches in diameter) can contain more than 1,500 mg of potassium.
- mushrooms; One cup of whole white mushrooms contains more than 300 mg.
- Peas. One cup of green peas contains 354 mg of potassium.
- Zucchini and zucchini. One medium zucchini contains 512 mg and a cup of butternut squash contains approximately 500 mg of potassium.
- Leafy green vegetables, such as Swiss chard and spinach. One cup of cooked Swiss chard contains 960 mg of potassium, and one cup of cooked spinach contains about 840 mg of potassium.
- gourd; One cup, boiled and mashed, contains 564 mg.
- beets; Half a cup of chopped beets contains 260 mg.
- Broccoli. One cup of raw broccoli contains approximately 300 mg.
- Football. Half a cup of boiled contains 247 mg.
- Carrots. One cup of shredded carrots contains 352 mg.
You can also find potassium in some fish, such as tuna, halibut, and cod. Oysters, meat and poultry also provide potassium. Beans and legumes, such as kidney beans, kidney beans and lentils, are also rich sources. Molasses, yogurt, cow’s milk, soy milk, pumpkin seeds, sunflower seeds, and nuts are good sources of potassium.
When grocery shopping, make a note of the potassium levels in the items you buy, which are clearly marked on the labels. “Checking the listed daily value for potassium can be helpful,” Holly says. “A Daily Value of 20% or more per serving indicates that the food is high in those nutrients.”
What happens if I don’t get enough potassium?
Potassium is a mild mineral – having too little of it can be deadly, just as eating too much of it can also be fatal. Therefore, it is very important to get the right balance. When you don’t have enough potassium in your diet, a condition called hypokalemia can develop. Hypokalemia can disrupt the delicate balance of electrical signals and lead to noticeable symptoms.
Symptoms of hypokalemia include:
- Muscle weakness, which if not treated can eventually turn into paralysis.
- Muscle twitching.
- Muscle cramps, especially at night.
- Abnormal or irregular heart rate, such as heart palpitations or atrial fibrillation.
- Mood changes and psychiatric symptoms including depression, psychosis or hallucinations have been linked to low potassium in extreme cases.
Holly notes that “the general US population does not reach the recommended daily amount of potassium each day due to eating large amounts of processed and packaged foods that tend to be low in nutrients. For this reason, the 2020-2025 Dietary Guidelines for Americans define potassium As an important nutrient for overall health in addition to calcium, vitamin D and dietary fiber.”
The National Institutes of Health also reports that most people in the United States do not get the recommended amount of potassium from their diet. In particular, people with inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis, and people with a rare eating disorder called pica — in which they usually or compulsively eat non-food items such as dirt or hair — tend to have difficulty getting enough. potassium;
Likewise, some medications change the way the body is able to regulate potassium levels, and you may end up excreting too much. For example, laxatives, blood pressure medications, and diuretics—medicines that flush excess fluid from the body—can lower potassium levels and lead to a deficiency.
Because potassium is water-soluble, it is excreted from the body through fluids, so vomiting, diarrhea, and excessive sweating, whether from intense exercise or hot weather, can reduce your stores of nutrients. Drinking alcohol and excessive caffeine intake can deplete potassium.
Holly recommends adopting the DASH diet, which stands for Dietary Approaches to Stop Hypertension. This diet provides a “great framework for incorporating more potassium into your diet” because it “encourages a diet rich in fruits, vegetables, whole grains, lean animal and plant proteins.” The DASH diet also recommends limiting sodium, sugar, and unhealthy fats: while its name suggests it’s meant for those with high blood pressure, many people can benefit from following this diet plan regardless of their high blood pressure concerns.
What happens if I have too much potassium?
Before making any adjustments to your diet, Holly says it’s best to speak with your primary care provider or a registered dietitian. With potassium, it is possible to eat a lot. Abnormally high levels of potassium cause a condition called hyperkalemia.
Symptoms of hyperkalemia include:
- Weakness and fatigue.
- Numbness and tingling in the extremities and extremities.
- Vomiting and nausea.
- Chest pain, palpitations, or irregular heartbeats.
Again, some medications can trigger this unusual condition, such as:
- Potassium-sparing diuretics, sometimes used to treat high blood pressure.
- ACE inhibitors, which are also used to treat high blood pressure.
- Non-steroidal anti-inflammatory drugs, such as ibuprofen and naproxen sodium.
- Heparin, an anticoagulant, or blood thinner.
It is possible to overdose on potassium, but this is unlikely to happen in a healthy person who simply eats a lot of potassium-rich foods because potassium is water soluble. This means that you are more likely to urinate from excess potassium levels.
However, some medications, such as potassium-sparing blood pressure medications, can increase the risk of developing hyperkalemia.
Should I take a potassium supplement?
“Unless your doctor prescribes a supplement, it’s best to get potassium from dietary sources,” Lyman says. But for some individuals, a supplement may be beneficial, and your doctor can help you find the right supplement for your condition.
Lyman notes that these products tend to deliver relatively low levels of potassium—by design. “The dose of potassium is intentionally very low, so you would have to take a lot of it to overdose or overdo it to a toxic level.”