Potassium

About Potassium

Potassium is the main cation inside cells, with about 98 percent of body potassium found intracellularly. Official adequate intakes vary by age, sex and life stage, and public health bodies encourage diets rich in potassium from fruits, vegetables and legumes. The sodium potassium pump, Na K ATPase, uses ATP to maintain the gradient of sodium and potassium across cell membranes that underlies nerve conduction and muscle contraction. Higher potassium intake is associated with lower blood pressure and lower stroke risk, and the DASH diet emphasizes potassium rich foods. Low blood potassium, hypokalemia, causes muscle weakness, cramps, constipation and arrhythmias, and usually results from diuretics, vomiting, diarrhea or excess aldosterone rather than poor intake. High blood potassium, hyperkalemia, causes characteristic ECG changes and can lead to dangerous arrhythmias and cardiac arrest, and usually results from kidney failure, certain medicines or Addison disease rather than diet. Modern Western diets tend to be lower in potassium and higher in sodium than the diets of early humans.