Potassium
Potassium (K)
TL;DR
Potassium is an essential electrolyte with strong evidence for lowering blood pressure — but food sources beat pills, and supplements are dose-capped for safety reasons.
Ideal For
- People with high sodium intake and elevated blood pressure
- Those with diuretic-induced low potassium (under medical supervision)
- Anyone eating few fruits and vegetables
Avoid If
- You have chronic kidney disease
- You take ACE inhibitors, ARBs, or spironolactone without monitoring
- You have Addison's disease
Frequently Asked Questions
Overview
Potassium sits alongside sodium as the primary determinant of cellular osmotic balance and membrane potential. Randomized trials and large meta-analyses (including WHO-commissioned reviews) show that raising potassium intake reduces systolic blood pressure by roughly 4-5 mmHg in hypertensive adults, with the largest effects in those consuming high-sodium diets. The DASH diet's benefit is substantially attributable to its potassium load. Deficiency (hypokalemia) causes muscle weakness, cramps, and arrhythmias, and is commonly triggered by loop or thiazide diuretics, vomiting, or diarrhea rather than by low intake alone. Because potassium is cleared by the kidneys, anyone with chronic kidney disease, or taking ACE inhibitors, ARBs, or potassium-sparing diuretics, can accumulate dangerous levels — hyperkalemia causes cardiac arrest. This is why supplements are limited to 99mg and why potassium-rich foods (potatoes, beans, leafy greens, avocado, yogurt) are the preferred route for most people. Potassium chloride salt substitutes have been shown in the large SSaSS trial to reduce stroke and cardiovascular death, but they carry the same renal cautions.
How It Works
- Maintains the Na+/K+ ATPase gradient that sets resting membrane potential
- Promotes natriuresis (sodium excretion), lowering extracellular fluid volume
- Improves endothelial function and reduces vascular stiffness
- Counterbalances sodium-driven fluid retention in the kidney
Supporting Research12 studies
Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women
Curhan GC, et al.
In 91,731 women followed for 12 years (864 incident stones), high dietary calcium intake was associated with a reduced risk of kidney stones (RR about 0.65 highest vs lowest quintile), whereas supplemental calcium use was associated with a modestly increased risk (RR about 1.20), particularly when taken apart from meals; high fluid and potassium intake were protective.
Magnesium, Calcium, Potassium, Sodium, Phosphorus, Selenium, Zinc, and Chromium Levels in Alcohol Use Disorder: A Review
Baj J
Review of mineral status in alcohol use disorder found consistently low magnesium, zinc and selenium levels and frequently disturbed calcium, potassium, sodium and phosphate balance, driven by poor intake, gastrointestinal losses, renal wasting and liver dysfunction; deficiencies were linked to withdrawal severity, neuropathy, arrhythmia risk and refeeding complications.
Potassium paraaminobenzoate (POTABA) in the treatment of Peyronie's disease: a prospective, placebo-controlled, randomized study
Weidner W, et al.
Potassium paraaminobenzoate appears to be useful to stabilize the disorder and prevent progression of penile curvature.
Effect of potassium citrate supplement on stone recurrence before or after lithotripsy: systematic review and meta-analysis
Carvalho M, et al.
Citrate supplementation effectively reduced nephrolithiasis recurrence in patients undergoing shockwave lithotripsy, though larger rigorous trials are needed.
Effect of Salt Substitution on Cardiovascular Events and Death (SSaSS)
Neal B, Wu Y, Feng X +29 more
Stroke, major cardiovascular events and death were all significantly lower with the potassium-enriched salt substitute
Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses
Aburto NJ, Hanson S, Gutierrez H +3 more
Higher potassium intake reduced systolic blood pressure by about 3.5 mmHg in hypertensive adults and was associated with a 24% lower risk of stroke
The impact of baseline potassium intake on the dose-response relation between sodium reduction and blood pressure change: systematic review and meta-analysis of randomized trials
Huang L, Neal B, Wu JHY +4 more
Sodium and potassium appear to interact with each other in their effects on blood pressure with potassium supplementation having a greater blood pressure lowering-effect when sodium intake is high.
Potassium supplementation for the management of primary hypertension in adults
Dickinson HO, Nicolson DJ, Campbell F +2 more
Potassium supplementation produced only small, non-significant reductions in blood pressure in the better quality trials
Potassium Intake and Blood Pressure: A Dose-Response Meta-Analysis of Randomized Controlled Trials
Filippini T, Naska A, Kasdagli MI +8 more
Blood pressure fell with increasing potassium intake up to about 90 mmol/day, with the strongest effects in hypertensive participants not on medication
Effects of oral potassium on blood pressure: meta-analysis of randomized controlled clinical trials
Whelton PK, He J, Cutler JA +4 more
Potassium supplementation reduced systolic blood pressure by 3.11 mmHg and diastolic by 1.97 mmHg, with larger effects in those with high sodium intake
Urinary sodium and potassium excretion, mortality, and cardiovascular events (PURE)
O Donnell M, Mente A, Rangarajan S +26 more
Higher estimated potassium excretion was associated with a lower risk of death and cardiovascular events
Potassium: Fact Sheet for Health Professionals
National Institutes of Health Office of Dietary Supplements
Most adults consume less potassium than recommended; over-the-counter supplements are generally limited to 99 mg per serving and high doses can cause hyperkalemia in kidney disease
Safety Information
Potential Side Effects
{"Nausea, GI upset, and rarely gastric ulceration with concentrated tablets"}
Contraindications
{"Chronic kidney disease","Hyperkalemia","Use of potassium-sparing diuretics without monitoring"}
Drug Interactions
- ACE inhibitors and ARBs (hyperkalemia risk)
- Potassium-sparing diuretics such as spironolactone
- NSAIDs (reduced renal potassium excretion)
Pregnancy & Breastfeeding
Pregnancy: likely_safe
Breastfeeding: likely_safe
Dosage Guidelines
Dosage Used in Studies
Consult healthcare provider
Forms Compared
Food & Timing
With food to reduce gastric irritation.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.