Fruits that contain this mineral include oranges and other citrus fruits, bananas, apples, avocados, raisins, and apricots, particularly dried. Whole grains, wheat germ, seeds, and nuts are high-potassium foods. Fish such as flounder, salmon, sardines, and cod are rich in potassium, and many meat foods contain even more potassium than sodium, although they often have additional sodium added as salt. Caffeine and tobacco reduce the absorption of potassium. People at risk for insufficient potassium intake include alcoholics, drug addicts and crash dieters.
Potassium is very important in the human body.
Along with sodium, it regulates the water balance and the acid-base balance in the blood and tissues. Potassium enters the cell more readily than does sodium and instigates the brief sodium-potassium exchange across the cell membranes. In the nerve cells, this sodium-potassium flux generates the electrical potential that aids the conduction of nerve impulses. When potassium leaves the cell, it changes the membrane potential and allows the nerve impulse to progress. Another of the pump's most important functions is preventing the swelling of cells.