The potassium ion is essential for the proper function of all cells and organs in the human body. Similar to sodium and chloride ions, the potassium ion is an electrolyte and therefore regulates fluid balance and is essential for electrical transmission in the body. Potassium ion levels in the body are tightly controlled, as abnormally high or low levels lead to ill health and potentially fatal consequences. Good sources of potassium include most fruits and vegetables, nuts and meats.
Muscle and Heart Function
Potassium is the main positively charged ion within cells and is needed for muscle contraction. The heart, being a muscle, is also dependent on adequate potassium levels. A review paper in the March 2011 issue of the "Journal of the American College of Cardiology" analyzed relevant studies published between 1966 and December 2009 and found that higher dietary potassium intake was associated with lower rates of stroke and coronary heart disease. The authors note that this supports recommendations to include plenty of potassium-rich foods in the diet.
Kidney Stones
Potassium appears to have a protective effect with regard to kidney stone formation. The August 2009 issue of "Pediatrics" carried a study investigating the efficacy of potassium citrate supplementation in reducing the risk of kidney stones in children on the ketogenic diet. This diet is used for a type of epilepsy, but is known to cause kidney stones in approximately 6 percent of the children started on this therapy. Potassium supplementation was found to be effective in preventing kidney stones in these patients and was not associated with any adverse effects.
Hyperkalemia
Hyperkalemia refers to abnormally high potassium levels in the body. This usually occurs when the body is unable to excrete it, for example in kidney failure, during heavy use of potassium-sparing diuretics and in endocrine disorders. It may also occur following high oral doses of potassium, usually from supplements. According to the "Oxford Handbook of Clinical Medicine," hyperkalemia causes muscular weakness, temporary paralysis and in serious cases, abnormal heart rhythm, which can lead to cardiac arrest.
Hypokalemia
On the other hand, hypokalemia refers to abnormally low potassium levels. It commonly occurs as a result of prolonged vomiting or diarrhea, during which considerable potassium is lost and is not replenished. It can also occur as a result of certain forms of kidney disease, from heavy use of some diuretics and in alcoholic patients. Hypokalemia can cause muscle weakness, constipation and abnormal heart rhythms.
References
- "Journal of the American College of Cardiology"; Potassium Intake, Stroke, and Cardiovascular Disease a Meta-analysis of Prospective Studies; L. D'Elia, et al.; March 2011
- "Pediatrics"; Empiric Use of Potassium Citrate Reduces Kidney-stone Incidence with the Ketogenic Diet; M.A. McNally, et al.; August 2009
- "Oxford Handbook of Clinical Medicine, 5th Edition"; M. Longmore, et al.; 2001
