Potassium is an essential dietary mineral, which must be tightly regulated to maintain normal body function. It is the main cation, an atom having a positive charge, in the fluid inside the cells. It is this positive charge that allows potassium to act as an electrolyte, conducting electricity throughout the body. It is needed for proper skeletal and smooth muscle function. Your heart cannot function properly without adequate amounts of potassium.
Heart Function
Low potassium, also known as hypokalemia, can cause heart palpitations or arrhythmias. The difference between the concentration of potassium and sodium inside the cells and in the fluid outside the cells creates an electrical gradient. Tight regulation of this cell membrane potential is crucial to heart function as well nerve impulse transmission and muscle contraction.
Risk of Deficiency
Hypokalemia is most often caused by extreme fluid loss due to prolonged vomiting and diarrhea or excess diuretic and laxative use. Conditions that may increase low potassium risk include kidney disease, congestive heart failure, anorexia, bulimia, metabolic disturbances and magnesium depletion.
Recommended Intake
Adequate intake of potassium has been set by the Institute of Medicine at 4,700 mg per day for most adult males and females. Breastfeeding women should get 5,100 mg per day from dietary intake.
Food Sources
Potassium is available in most plant foods. A medium baked potato with the skin provides close to 1,000 mg and a 1/2 cup serving of raisins provides around 600 mg. Other foods containing more than 400 mg per serving include bananas, prune juice, dried plums, tomato juice, Lima beans and spinach.
