Everything You Need To Know About Potassium

Potassium is an essential mineral that supports a number of bodily functions. However, it’s a nutrient that Americans don't consume enough of. If anything, Americans tend to fall below the recommended intakes for potassium, so the 2015-2020 Dietary Guidelines for Americans said it as a nutrient of concern.

Keep reading to learn why potassium is important, how much you need, and good sources of it.

Why Do You Need Potassium?

Potassium is a mineral that plays an important role in a variety of bodily functions, from healthy heart function to kidney function. It’s even a key nutrient in the Dietary Approaches to Stop Hypertension (DASH) diet, a therapeutic diet for hypertension management, partly because of its relationship to sodium. Potassium works with sodium to maintain intracellular fluid volume, which is the fluid content within your body's cells.

Potassium is especially important for:

• Kidney function
• Heart function
• Muscle contraction
• Nerve transmission
• Intracellular fluid volume

If you don’t consume enough potassium, there are a few potential consequences, including:

• Increased blood pressure
• Reduced calcium in bones
• Increased risk of kidney stones

Cardiac arrhythmias and cardiac arrest could occur as a result of refeeding syndrome—a condition caused by malnutrition. Refeeding syndrome happens when someone has been malnourished and sources of energy, particularly carbohydrates, are reintroduced too quickly, causing rapid fluid and electrolyte shifts. Potassium is one of those electrolytes of concern, since it can rapidly shift from the blood into cells, causing severe hypokalemia (lower than normal potassium in your bloodstream) and potentially death.

How Much Potassium Do You Need?

The adequate intakes (AIs) for potassium vary based on your age, sex, and whether you’re pregnant or lactating.

Males

For males, here are the AIs for potassium based on age group:

• Birth–6 months: 400 milligrams (mg)
• 7–12 months: 860 mg
• 1–3 years: 2,000 mg
• 4–8 years: 2,300 mg
• 9–13 years: 2,500 mg
• 14–18 years: 3,000 mg
• 19–50 years: 3,400 mg
• 51+ years: 3,400 mg

Females

Here are the AIs for potassium based on age group for females:

• Birth–6 months: 400 mg
• 7–12 months: 860 mg
• 1–3 years: 2,000 mg
• 4–8 years: 2,300 mg
• 9–13 years: 2,300 mg
• 14–18 years: 2,300 mg
• 19–50 years: 2,600 mg
• 51+ years: 2,600 mg

Pregnancy and Lactation

For individuals who are pregnant or lactating, the AIs are a bit different. For lactating individuals 14–18 years old, the AI is 2,500 mg, and for those 19–50 years old, it’s 2,800 mg.

For pregnant individuals 14–18 years old, the AI is 2,600 mg, and for those 19–50 years old, the AI is 2,900 mg.

What Foods Are High in Potassium?

Potassium is found in a wide variety of foods including fruits, vegetables, beans, dairy products, and meat. Here are some of the best sources of potassium:

• Dried apricots: 16% daily value (DV) in ½ cup
• Lentils: 16% DV in 1 cup cooked
• Mashed acorn squash: 14% DV in 1 cup
• Dried prunes: 14% DV in ½ cup
• Baked potato: 13% DV in 1 medium, flesh only
• Kidney beans: 13% DV in 1 cup
• Orange juice: 11% DV in 1 cup

In the U.S. and the U.K., potatoes and savory snacks, potassium-containing drinks (fruit juice, beer, coffee, and tea), meat products, cereal, and milk contribute the most to people’s potassium intakes.

You can also up your potassium intake through dietary supplements. However, it’s generally recommended that you increase your potassium intake through fruits and vegetables, especially since these food groups have a number of other health benefits.

Symptoms Of And Treatment For Low Potassium

The 2013-2014 version of the National Health and Nutrition Examination Survey (NHANES) revealed that for adults 20 and over, the average daily potassium intake is 3,016 mg for men and 2,320 mg for women (about 300–400 mg below the AIs for adults aged 19–50 years old).

However, having dangerously low potassium usually isn’t caused by inadequate intake of potassium alone; it’s often a result of diarrhea, vomiting, refeeding syndrome, diuretics, heavy sweating, or laxative abuse. 

Hypokalemia (low potassium) is diagnosed through a blood test, and it’s characterized by serum potassium levels below 3.6 millimoles per liter (mmol/L). Symptoms of low potassium start to be experienced below 3 mmol/L and include constipation, fatigue, and muscle weakness in mild cases, and polyuria (excessive urine production), glucose intolerance, muscular paralysis, poor respiration, and cardiac arrhythmias in severe cases where serum levels are less than 2.5 mmol/L.

Recommended treatment for hypokalemia can include a combination of potassium tablets and infusions for mild to moderate cases, and intravenous replacement for severe cases.

Symptoms Of And Treatment For High Potassium

Believe it or not, there’s no tolerable upper limit (UL) for potassium. If you have healthy kidneys, excess potassium is typically excreted effectively in your urine and your body maintains a normal serum potassium range of 3.5–5.0mmol/L.

For those with chronic kidney disease or who are taking ACE inhibitors or angiotensin receptor blockers, excess potassium can be harmful because the kidneys’ suboptimal functioning hinders them from excreting the excess potassium in your urine. In fact, in these cases, potassium usually needs to be restricted to amounts below the AIs.

Many times, people with hyperkalemia (high potassium) don’t have any symptoms. If they do, symptoms typically include muscle weakness, numbness, tingling, or nausea.

Treatment for hyperkalemia may include intravenous calcium, insulin, or diuretics. Potassium binders—powders taken with food that help bind and excrete extra potassium—may also be used. If the root cause of hyperkalemia is kidney disease or another severe kidney issue, dialysis may be warranted.

A Quick Review

Potassium is an essential mineral that most Americans don't get enough of. It’s found in a variety of foods including dried fruits, vegetables, legumes, milk, and meat. Supplementation is another option for boosting potassium intake. 

While there’s no established tolerable upper limit for potassium intake, excess intake can pose big issues for those with kidney disease or on certain medications. 

A healthcare provider can check your blood potassium levels if warranted to assess your levels and determine if there is a health issue that requires you to consume more or less than the adequate intakes.