Potassium

What does potassium do?

Potassium is needed to regulate water balance, levels of acidity, blood pressure, and neuromuscular function. It’s also required for carbohydrate and protein metabolism.

Where is potassium found?

Most fruits are excellent sources of potassium. Beans, milk, and vegetables contain significant amounts of potassium.

Who is likely to be deficient in potassium?

So-called primitive diets provided much greater levels of potassium; modern diets may provide too little. Gross deficiencies, however, are rare except in cases of prolonged vomiting, diarrhea, or use of “potassium depleting” diuretic drugs. People taking one of these drugs should be informed by their doctor to take potassium. Prescription levels of potassium are higher than the amount sold over the counter but not more than the amount found in several pieces of fruit.

How much potassium is usually taken?

The best way to get extra potassium is to eat several pieces of fruit per day. The amount allowed in supplements—99 mg per tablet or capsule—is very low, considering that one banana can contain 500 mg. Multiple potassium pills should not be taken in an attempt to get a higher amount, because they can irritate the stomach—a problem not encountered with the potassium in fruit.

Are there any side effects or interactions?

High potassium intake (several hundred milligrams at one time in tablet form) can produce stomach irritation. People using potassium-sparing drugs should avoid the use of potassium chloride-containing products, such as Morton Salt Substitute®, No Salt®, Lite Salt®, and others. Even eating several pieces of fruit per day can sometimes cause problems for people taking potassium-sparing diuretics, due to the high potassium content of fruit.

Potassium and sodium work together in the body to maintain muscle tone, blood pressure, water balance, and other functions. Many researchers believe that part of the blood pressure problem caused by too much salt (which contains sodium) is made worse by too little dietary potassium.