Potassium is the most abundant positively charged ion (cation) inside cells, where it reaches concentrations of approximately 140 mEq/L — about 30 times higher than in extracellular fluid. This steep concentration gradient, maintained by the sodium-potassium ATPase pump, is fundamental to the resting membrane potential of cells — particularly neurons and muscle cells — and is essential for the generation of action potentials that allow muscles to contract and nerves to fire.
Why potassium matters for blood pressure
The relationship between potassium and blood pressure is one of the most consistently supported findings in nutritional epidemiology. Higher potassium intake is associated with lower blood pressure in population studies, and intervention trials confirm a causal relationship. The mechanism involves several pathways: potassium promotes renal sodium excretion (reducing blood volume), induces vasodilation (relaxing blood vessel walls), and reduces arterial stiffness.
The sodium-to-potassium ratio in the diet appears to be more predictive of blood pressure and cardiovascular risk than either mineral alone. The World Health Organization recommends a daily potassium intake of at least 3,510 mg, yet dietary surveys consistently find that the majority of adults worldwide fall short of this target, while simultaneously consuming excess sodium.
Dietary sources
Potassium is found in abundance in whole, unprocessed foods: bananas, sweet potatoes, white potatoes, avocados, beans, lentils, leafy greens, salmon, and dairy products are all significant sources. The reason most people in modern diets fall short is the displacement of these whole foods by ultra-processed foods — which are high in sodium and low in potassium.
Why supplements have low doses
If you have looked at a potassium supplement and noticed that each capsule contains only 99 mg — roughly 2% of the recommended daily intake — there is a regulatory reason. In the United States, the FDA mandates that over-the-counter potassium supplements contain no more than 99 mg per serving (with the exception of potassium chloride salt substitutes). This limit exists because high-dose potassium supplements taken on an empty stomach can cause gastrointestinal irritation, and, in rare cases, people with kidney disease or who take ACE inhibitors or potassium-sparing diuretics can develop hyperkalaemia (dangerously high blood potassium) from supplemental potassium. For most healthy individuals, food remains the best source of potassium.
Common supplement forms
Potassium supplements come in several forms: potassium citrate (alkalising, sometimes used in kidney stone management), potassium gluconate (mild, common in tablets), and potassium chloride (available as salt substitutes for cooking). Potassium citrate is the most commonly recommended form for supplementation due to its alkalising effect, which may reduce renal calcium excretion.
Potassium supplements in Lebanon
Supplements & More carries potassium supplement capsules from US brands, available with cash on delivery across Lebanon.