Most adults need between 2,600 and 3,400 milligrams of potassium per day, depending on age and sex. Adult men 19 and older need 3,400 mg, while adult women in the same age range need 2,600 mg. These are the Adequate Intake values set by the National Institutes of Health, and most people fall short of them.
Recommended Daily Intake by Age and Sex
Potassium needs increase steadily from infancy through adulthood. Children ages 1 to 3 need about 2,000 mg per day, rising to 2,300 mg for ages 4 to 8. By the teenage years, boys and girls start to diverge: boys 14 to 18 need 3,000 mg, while girls the same age need 2,300 mg. That gap persists into adulthood, with men settling at 3,400 mg and women at 2,600 mg for the rest of their lives.
Pregnancy and breastfeeding raise the target modestly. Pregnant women need 2,900 mg per day, and breastfeeding women need 2,800 mg. The World Health Organization sets a slightly different benchmark, recommending at least 3,510 mg per day for all adults, regardless of sex. The difference comes down to methodology, but either way, most people in Western countries eat less potassium than any of these guidelines suggest.
Why Potassium Matters for Blood Pressure
Potassium’s most well-studied role is its relationship with sodium and blood pressure. When you eat enough potassium, it helps your kidneys flush out excess sodium through urine. This happens because potassium deactivates a specific sodium-reabsorbing channel in the kidneys, so more sodium leaves your body instead of being pulled back into your bloodstream.
When potassium intake is low, the opposite occurs. That same kidney channel stays active even when sodium intake is high, causing your body to hold onto more sodium and water. The result is higher blood volume and higher blood pressure. This is why focusing only on cutting sodium can miss half the equation. Increasing potassium intake has been shown to lower blood pressure in people with hypertension.
Best Food Sources of Potassium
The richest potassium sources are vegetables, legumes, and starchy tubers. A single cup of cooked beet greens delivers 1,309 mg, nearly half the daily target for an adult man. Cooked Swiss chard provides 961 mg per cup, and a cup of cooked lima beans comes in at 955 mg. A medium baked potato with the skin gives you 926 mg, making it one of the most practical everyday sources.
Other strong options include cooked yam (911 mg per cup), acorn squash (896 mg per cup), and cooked spinach (839 mg per cup). Fruits like bananas get the most attention, but they’re actually moderate sources compared to these vegetables and legumes. Reaching 2,600 to 3,400 mg through food is realistic if you regularly include a few of these high-potassium items throughout the day.
Potassium Needs During Exercise
You lose potassium through sweat, and the amount scales with exercise intensity. Research on trained endurance athletes found that low-intensity exercise caused potassium losses of about 359 mg per hour. At moderate intensity, losses rose to roughly 485 mg per hour, and high-intensity exercise pushed them to about 581 mg per hour. That’s a 50% increase from low to high intensity.
For most people doing a standard workout, this isn’t dramatic enough to require supplements. But if you’re training hard for over an hour, especially in heat, your daily potassium needs effectively increase. Eating potassium-rich foods after exercise is generally enough to replace what’s lost.
Can You Get Too Much Potassium?
For people with healthy kidneys, getting too much potassium from food alone is extremely rare. Your kidneys are efficient at clearing excess potassium from the bloodstream, so dangerously high levels almost never result from diet in people with normal kidney function. No formal upper limit has been established for potassium intake in healthy individuals.
The risk changes significantly if your kidneys aren’t working well. Impaired kidneys can’t excrete potassium efficiently, allowing levels to build up in the blood. People with chronic kidney disease are typically advised to limit potassium to 2,000 to 2,500 mg per day, well below the general recommendations. Salt substitutes, which often replace sodium chloride with potassium chloride, can also push levels higher and are worth watching if kidney function is compromised.
Supplements vs. Food
Over-the-counter potassium supplements in the U.S. are capped at relatively low doses, typically around 99 mg per tablet. That’s a fraction of what you’d get from a single baked potato. This cap exists because concentrated potassium in pill form can irritate the digestive tract and, in large doses, cause a dangerous spike in blood potassium levels that food sources don’t produce. Food delivers potassium gradually, packaged alongside fiber, water, and other minerals that help your body absorb and manage it.
For most people, closing the gap between what they eat and what they need is better accomplished by adjusting their diet than by taking supplements. Adding one or two high-potassium foods to your daily meals can easily cover 500 to 1,000 mg of the shortfall.