Potassium is an abundant mineral in the body and is necessary for the proper functioning of the kidneys. It also is active in smooth, skeletal and cardiac muscle contraction. High blood pressure, heart disease and arthritis may result from a deficiency in potassium. Processed food and added salt to the diet can result in a deficiency of potassium. Vegetarians, athletes, smokers and women who take oral contraceptives may benefit from supplementing potassium. It is most typically used for hypokalemia, which shows itself in an abnormal EKG, irregular heartbeat, muscle cramps, low energy and weakness. It may also help treat asthma, inflammatory bowel disease, stroke, high blood pressure and osteoporosis.