Potassium (K) - Nutrition Minerals

Potassium (K)

Potassium is an electrolyte found primarily in intracellular fluid. Like sodium, it is essential for fluid balance and osmosis. Potassium maintains the fluid level within the cell, and sodium maintains the fluid level outside the cell.Osmosismoves the fluid into and out of cells as needed to maintain electrolyte (and fluid) balance. 

There is normally more potassium than sodium inside the cell and more sodium than potassium outside the cell. If this balance is upset and the sodium inside the cell increases, the fluid within the cell also increases, swelling it and causing edema. If the sodium level outside the cell drops, fluid enters the cell to dilute the potassium level, thereby causing a reduction in extracellular fluid. With the loss of sodium and reduction of extracellularfluid, a decrease in blood pressure and dehydration can result.

Potassium is also necessary for transmission of nerve impulses and for muscle contractions.

Sources.Potassium is found in many foods. Fruits—especially melons,oranges, bananas, and peaches—and vegetables—notably mushrooms, Brus-sels sprouts, potatoes, tomatoes, winter squash, lima beans, and carrots—are particularly rich sources of it.

Deficiency or Excess.

Potassium deficiency (hypokalemia) can be caused by diarrhea, vomiting, diabetic acidosis, severe malnutrition, or exces-sive use of laxatives or diuretics. Nausea, anorexia, fatigue, muscle weakness, and heart abnormalities (tachycardia) are symptoms of its deficiency. Hyper-kalemia (high blood levels of potassium) can be caused by dehydration, renalfailure, or excessive intake. Cardiac failure can result.