Know2eat

Potassium

Minerals

What potassium may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedHealthy blood pressureStrong evidence· 4 sources

Then, in order

About Potassium

The principal intracellular electrolyte, essential for nerve conduction, muscle contraction and blood pressure regulation. Over-the-counter supplements in the US are limited to 99 mg per tablet, a small fraction of daily need.

Potassium is the unusual case of a nutrient where the evidence for higher intake is genuinely strong and the supplement is genuinely restricted. Randomised trials and meta-analyses show that increasing potassium intake lowers blood pressure, particularly in people with hypertension and high sodium intake, and WHO issued a guideline recommending increased potassium consumption on that basis. But most adults fall well short of the Adequate Intake of 2,600–3,400 mg/day, and a 99 mg tablet contributes about 3% of it. The regulatory limit exists because concentrated potassium can cause gastrointestinal ulceration and dangerous hyperkalaemia. This is a nutrient where the food route is not merely preferable but practically the only workable one.

Sold as
99 mg tablet or capsule, Prescription modified-release potassium chloride, Potassium citrate (prescription for stones), Salt substitute, Electrolyte powder
Also known as
Potassium chloride, Potassium citrate, Potassium gluconate, K

Regulation: The FDA restricts non-prescription solid oral potassium products to 99 mg per dosage unit, because higher-strength tablets caused small-bowel ulceration. Higher-dose potassium chloride is prescription-only. The Adequate Intake is 2,600 mg/day for women and 3,400 mg/day for men; no Tolerable Upper Intake Level has been set for healthy adults, since the kidneys handle dietary potassium efficiently.

What the research used

The amounts, forms and durations published trials of Potassium actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Adequate Intake, adults

    2600–3400 mg

    Strong

    2,600 mg/day for women and 3,400 mg/day for men, revised downward in 2019 from the earlier 4,700 mg figure. Most adults in Western countries consume substantially less.

  • Studied for Blood pressure trials

    1500–4700 mg

    Strong

    Supplemental potassium, usually chloride, daily · 4 weeks–6 months

    Trials used prescription-strength doses far above the 99 mg over-the-counter limit. Effects were largest in people with hypertension and high sodium intake, and small or absent in people with normal blood pressure.

  • Studied for Over-the-counter supplement

    99 mg

    Moderate

    Tablet

    Roughly 3% of the Adequate Intake — the regulatory cap makes over-the-counter potassium nutritionally trivial, which is worth knowing before buying it.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

Each timing below was actually compared against an alternative in a trial, which is unusual.

  • With food

    Moderate

    Potassium salts irritate the gastrointestinal tract and are taken with food and plenty of water to reduce that. Established practice from the ulceration problems that prompted the dose restriction.

    Timing was tested. A trial compared this window against another and reported a difference.

The evidence in depth

Best supported: Strong

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Healthy blood pressure

Heart Health
Strong evidence

Increasing potassium intake lowers blood pressure in randomised trials, consistently across meta-analyses, with the largest effects in people with hypertension and high sodium intake and little effect in people with normal blood pressure. WHO issued a guideline recommending increased potassium intake on this evidence. Reaching the intakes used in trials requires food or prescription-strength products, not 99 mg tablets.

What may be going on: Potassium promotes urinary sodium excretion, relaxes vascular smooth muscle and counters the pressor effect of a high sodium intake.

Strong evidence. Consistent findings across multiple good-quality human studies.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Kidney and urinary function

Kidney & Urinary Health
Moderate evidence

Potassium citrate is used clinically to raise urinary citrate and reduce recurrence of calcium kidney stones, supported by randomised trials. That is a prescription intervention rather than a shelf supplement.

Moderate evidence. Several human studies point the same way, with real caveats.

View the 2 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Bone mineral density

Bone Health
Limited evidence

Alkaline potassium salts reduce urinary calcium loss and some trials report small effects on bone turnover markers. Evidence for changes in bone density or fractures is weak.

Limited evidence. Early human work, or mostly lab and animal research.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Too much

    Hyperkalaemia can cause cardiac arrest

    High blood potassium disturbs cardiac conduction and can cause fatal arrhythmia, often with few warning symptoms beyond weakness or palpitations. The risk concentrates in people with reduced kidney function, in whom potassium clearance is impaired, and in anyone combining supplements with potassium-retaining medication.

  • Interaction

    Serious interactions with common blood pressure and heart drugs

    Interacts withACE inhibitors, angiotensin receptor blockers, spironolactone, amiloride, trimethoprim, NSAIDs

    ACE inhibitors, angiotensin receptor blockers, potassium-sparing diuretics such as spironolactone and amiloride, trimethoprim, heparin and NSAIDs all raise blood potassium. Adding a supplement or a potassium-based salt substitute on top of these is a recognised route to dangerous hyperkalaemia.

  • Avoid

    Chronic kidney disease

    In moderate to severe kidney disease, potassium restriction rather than supplementation is usually required. Salt substitutes are largely potassium chloride and are a frequently overlooked source in this group.

  • Too much

    Gastrointestinal ulceration

    Concentrated potassium salts caused small-bowel ulceration and bleeding, which is why over-the-counter tablets are capped at 99 mg. Nausea, vomiting and abdominal pain are common at higher doses even in modified-release forms.

In the food catalogue

The whole-food form, where one exists. The evidence for a concentrated extract rarely transfers to the food, or the other way round — these are cross-links, not equivalents.

BananaThe food most associated with potassium, though many vegetables and…Cannellini beansA dense legume source.PotatoOne of the highest-potassium everyday foods, well above a banana per…

Evidence ratings on this page: 1 strong evidence, 1 moderate evidence, 1 limited evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Potassium, or a dose to follow.