Potassium

Electrolyte · cell charge

What does Potassium do in your body?

The main positive ion inside your cells. Its gradient across cell membranes lets nerves fire and muscles — including your heart — contract.

How it works, step by step

1. Absorbed easily in the small intestine.
2. Sodium–potassium pumps move potassium into cells using ATP.
3. A nerve fires: sodium rushes in, then potassium flows out to reset.
4. Kidneys excrete what isn't needed.

What does Potassium do?

Pumps in every cell membrane push potassium in and sodium out. That difference is the electrical charge nerves and muscles use to send signals.

Where does Potassium act in the body?

Inside every cell — especially nerves, skeletal muscle and heart. Kidneys keep blood levels in a narrow range.

Which foods contain Potassium?

Beans, lentils, potatoes, dried apricots, bananas, spinach, avocados, yogurt, milk, salmon.

How much Potassium do adults need?

Adequate Intake: 3,400 mg (men), 2,600 mg (women). No upper limit set for food.

What happens with too little Potassium?

Low intake is common; low blood potassium is usually from vomiting, diarrhea or diuretics, not diet alone.

Can you get too much Potassium?

High blood potassium is mainly a risk with reduced kidney function or medicines like ACE inhibitors — this needs clinical guidance.

What does Potassium interact with?

Diets high in potassium partly offset sodium's effect on blood pressure.

What is known and unknown about Potassium?

Membrane physiology is established. Higher potassium intake is associated with lower blood pressure.

Evidence & sources

• Adequate Intake for adults is 3,400 mg/day (men) and 2,600 mg/day (women). Evidence: regulatory. Known: Set by the National Academies in 2019 as an Adequate Intake. Unknown: An AI is not a precise requirement. Source: National Academies of Sciences, Engineering, and Medicine, Dietary Reference Intakes for Sodium and Potassium (2019).
• Potassium gradients are essential for nerve transmission and muscle contraction. Evidence: established. Known: Core, well-established cell physiology. Unknown: — Source: NIH Office of Dietary Supplements, Potassium — Health Professional Fact Sheet (Current revision).

Connected topics

• Banana
• Spinach
• Lentils
• Nerve Signaling
• Skeletal Muscle
• Heart
• Kidneys
• Sodium
• Potato

Try it in your browser

General education only, not medical advice. Drafted Oct 2026 · pending qualified expert review.