Potassium is a mineral and electrolyte that helps your nerves, muscles and heart work properly and helps balance blood pressure. Many people eat less than the recommended amount, yet too much can be dangerous for people with kidney disease or those taking certain medicines. This guide covers daily needs, food sources, signs of low and high potassium and medicine interactions, based on the NIH Office of Dietary Supplements consumer fact sheet.
How Much Potassium Do You Need Each Day?
The NIH lists these adequate daily intakes:
- Children 1 to 3 years: 2,000 mg; 4 to 8 years: 2,300 mg
- Boys 9 to 13 years: 2,500 mg; girls 9 to 13 years: 2,300 mg
- Teen boys 14 to 18 years: 3,000 mg; teen girls 14 to 18 years: 2,300 mg
- Adult men: 3,400 mg; adult women: 2,600 mg
- Pregnant women: 2,900 mg (2,600 mg for pregnant teens)
- Breastfeeding women: 2,800 mg (2,500 mg for breastfeeding teens)
Best Food Sources of Potassium
- Dried apricots, prunes and raisins, orange juice and bananas
- Acorn squash, potatoes, spinach, tomatoes and broccoli
- Lentils, kidney beans, soybeans and nuts
- Milk and yogurt
- Meat, poultry and fish
Signs of Low Potassium
The NIH notes that the diets of many people in the United States provide less than the recommended amounts. Low intake can raise blood pressure, drain calcium from bone and increase the risk of kidney stones. Low blood potassium (hypokalemia) can cause constipation, tiredness, muscle weakness and a general feeling of being unwell. Severe hypokalemia can cause increased urination, reduced brain function, high blood sugar, paralysis, breathing difficulty and irregular heartbeat, and can be life threatening.
- People with inflammatory bowel disease
- People who use laxatives or certain diuretics
- People who eat non-food items (pica)
Too Much Potassium (Hyperkalemia)
The NIH says potassium from food and drinks has not been shown to cause harm in healthy people with normal kidney function. High blood potassium is a risk for people with:
- Chronic kidney disease
- Use of ACE inhibitors or potassium-sparing diuretics
- Type 1 diabetes, congestive heart failure, liver disease or adrenal insufficiency
Even healthy people can develop high potassium from supplements or salt substitutes if they take more than the body can remove.
Salt Substitutes and Supplements
Many salt substitutes contain potassium. If you have kidney disease or take certain medicines, these products could push your potassium too high, so check with your doctor first. Over-the-counter potassium supplements are limited to no more than 99 mg per serving.
Potassium and Medicine Interactions
- ACE inhibitors (such as benazepril) and ARBs (such as losartan) can raise potassium levels.
- Potassium-sparing diuretics (such as amiloride and spironolactone) can raise potassium levels.
- Loop diuretics (such as furosemide and bumetanide) and thiazide diuretics (such as chlorothiazide and metolazone) can cause abnormally low potassium.
Never stop or change a prescribed medicine on your own. Ask your doctor whether your potassium should be checked.
When to See a Doctor
- You have constant tiredness, muscle weakness or cramps with no clear reason
- You have kidney disease, heart failure or diabetes
- You take blood pressure medicines or diuretics and want to use a salt substitute or supplement
- You notice an irregular heartbeat
Frequently Asked Questions
How much potassium do adults need per day?
Adult men need 3,400 mg and adult women need 2,600 mg a day, according to the NIH.
Which foods are rich in potassium?
Dried apricots, prunes, raisins, orange juice, bananas, potatoes, spinach, tomatoes, beans, lentils, nuts, milk, yogurt, meat and fish.
What are the signs of low potassium?
Constipation, tiredness, muscle weakness and feeling unwell. Severe low potassium can cause paralysis and an irregular heartbeat.
Who should be careful with potassium?
People with kidney disease, and those taking ACE inhibitors, ARBs or potassium-sparing diuretics, because their potassium can rise too high.
Are salt substitutes safe?
Many contain potassium, which can be unsafe if you have kidney disease or take certain medicines. Check with your doctor first.
Related reading: Magnesium daily needs and safety | Calcium daily needs and supplements | Vitamin D daily needs and sources
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Medical disclaimer: this article is for general information and does not replace advice from a qualified doctor. Do not start, stop or change any supplement or medicine without medical advice.