Potassium
MineralFoundational
The main mineral inside your cells, and the counterweight to sodium.
At a glance
Essential · most people run low
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Keeps nerves and muscles firing
Holds the electrical charge across every cell membrane.
why ↓
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Steady heart rhythm
Needed for normal heart contractions.
why ↓
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Balances sodium
The two together control fluid balance.
why ↓
Strong human evidence
How to take it
- 2,600–3,400 mg a day, from food
- Baked potato, tomato, spinach, banana, avocado, orange juice
Watch out
- Keep supplement doses small. High-dose potassium is a heart risk.
- Diuretics and GI illness drain it
Signs you're low
- Weakness, cramps, constipation
- Irregular heartbeat
The Research
Mechanisms, studies and evidence grades for each claim above.
Functions
- Maintains resting membrane potential
- Supports cardiac rhythm and muscle contraction
- Balances sodium for fluid/electrolyte homeostasis — see Sodium
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Mechanism
Works opposite sodium via the Na⁺/K⁺-ATPase pump to maintain electrochemical gradients across the cell membrane.
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Intake
Adequate intake roughly 2,600 mg/day (women) and 3,400 mg/day (men). Emphasize food sources — supplements are typically capped per dose for safety reasons (rapid IV or high-dose oral potassium is a real cardiac risk).
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Deficiency effects
Low potassium (often from losses via sweat, GI illness, or diuretic medications) can cause weakness, cramps, constipation, and arrhythmias; severe hypokalemia can be dangerous.
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Top foods
- Potato (baked)
- Tomato
- Spinach
- Banana
- Avocado
- Orange
- Orange juice
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