Potassium is one of the electrolyte minerals. It is important in maintaining the body's acid-base and fluid balance. Potassium works very closely with sodium and chloride, which are also electrolyte minerals. These three minerals are in all fluids of the body. Potassium is found in fluids within cells. The other two are found in fluids outside of cells.
A deficiency of potassium in the diet is unlikely and generally rare. Potassium deficiency can occur because of vomiting, diarrhea and long-term laxative and diuretic use. Low potassium levels can also be caused by chronic disease and the aging process. Kidney problems can cause a severe loss of potassium. Common problems associated with low potassium levels include:
high blood pressure or hypertension
irregular heart rhythms called cardiac arrhythmias
People taking medication for high blood pressure, such as diuretics, may need to take a potassium supplement. These individuals should consult their healthcare provider.
The body protects itself from potassium toxicity by dissolving and excreting the mineral. In severe cases, a person will vomit, to keep blood levels within safe limits. When blood levels of potassium start to measurably rise it is called hyperkalemia. This is usually due to a specific cause such as reduced kidney function, increased protein breakdown or severe infection. If excess potassium cannot be excreted, it can cause heart problems. People with kidney problems may not be able to excrete excess amounts. They may be put on a potassium-restricted diet. They need to be careful of salt-substitutes. Salt-substitutes are usually made of potassium chloride. Regular salt is made from sodium chloride.
There is no Recommended Daily Allowance (RDA) for potassium. The minimum amount suggested for adults is 2,000 milligrams (mg) per day. Some experts suggest a level of about 3,500 mg per day to help protect against high blood pressure. The typical American adult gets between 800 mg and 1,500 mg per day. Following the Food Guide Pyramid should ensure a safe amount of daily potassium.