Potassium is a mineral involved in electrical and cellular body functions. In the body, potassium is classified as an electrolyte.

Potassium is a very important mineral to the human body. It has various roles in metabolism and body functions and is essential for the proper function of all cells, tissues, and organs:

• It assists in the regulation of the acid-base balance.
• It assists in protein synthesis from amino acids and in carbohydrate metabolism.
• It is necessary for the building of muscle and for normal body growth.

Fish such as salmon, cod, flounder, and sardines are good sources of potassium. Various other meats also contain potassium.

Vegetables including broccoli, peas, lima beans, tomatoes, potatoes (especially their skins), and leafy green vegetables such as spinach, lettuce, and parsley contain potassium.

Fruits that contain significant sources of potassium are citrus fruits, apples, bananas, and apricots. Dried apricots contain more potassium than fresh apricots.

Patients on dialysis for kidney failure should avoid excess consumption of these foods. These patients require specialized diets to avoid excess potassium in the blood (hyperkalemia).

A deficiency of potassium (hypokalemia) can occur in people with certain diseases or as a result of taking diuretics for the treatment of high blood pressure or heart failure. Diuretics are probably the most common cause of hypokalemia. The most common problems associated with reduced potassium levels are electrocardiogram (ECG) changes, weakness, and  fatigue; also, cardiac arrhythmias (irregular heart beats) could be a concern.

A variety of conditions can cause the loss of potassium from the body. The most common of these conditions are vomiting and diarrhea.

Kidney disease (such as acute renal failure) and diabetes, depending on the stage of either disease, can also cause fluctuations in the levels of potassium. Additionally, many medications -- such as diuretics, laxatives, and steroids -- can cause depletion of potassium.

The most common symptom of potassium depletion is fatigue. Other symptoms of potassium deficiency include slow reflexes, muscle weakness, and EKG changes. A quick loss of potassium could lead to cardiac arrhythmias.

Symptoms of severe potassium deficiency include decreased heart rate, extreme muscle weakness, and, if untreated, death. A low level of potassium can be determined with a blood test and can be treated with potassium supplements.

Increased levels of potassium in the blood is known as hyperkalemia. Some common causes of this are reduced renal (kidney) function, an abnormal breakdown of protein, and severe infection. The most common cause of hyperkalemia is reduced kidney function, especially in patients receiving dialysis for kidney failure.

Muscle breakdown from heat, exercise, or medications may rarely occur, and can cause hyperkalemia. Rarely, during vigorous exercise, especially if the person is dehydrated, excess potassium intake in food or supplements can cause hyperkalemia.

The recommended daily allowance for potassium is 3.5 grams per day. The average American diet provides 2 to 6 grams of potassium per day.

Over-the-counter potassium supplements provide 99 milligrams of potassium per tablet. It would require 35 tablets to meet the recommended daily allowance. Supplementation is not recommended without specific approval and instruction from your doctor. 

Certain patients being treated for hyperkalemia, usually due to diuretics or specific diseases, are given very specific potassium supplementation regimens by their doctor, based on their individual needs.