Question: My doctor says that my leg cramps are from being low in potassium. Are there certain foods that have a lot of potassium? Can I eat too much potassium?
Potassium is a mineral that is important for the body to function properly. Potassium is the element 19 on the periodic table and is represented by the symbol "K." Almost all the potassium in the body is found inside the cells rather than outside in the body's fluids like blood. The kidneys are crucial to regulating the amount of potassium in the body. Potassium is excreted by the kidneys as well as the gastrointestinal tract.
Potassium helps maintain water and pH balance. It has a role in nervous system function allowing signals to be sent from one nerve cell to the next. Potassium is also a key player in allowing muscle contractions. Potassium often works in conjunction with sodium in the cells to generate signals for body processes.
According to the Institute of Medicine guidelines, the recommended daily intake for potassium in teenagers and adults is 4700 mg. Infants should have 400-700 mg per day while children should have 3000-4500 mg. Potassium is found in many foods. Natural sources of potassium include meat, milk, fruits, and vegetables. A 3-oz. pork chop and one cup of fat-free milk each have about 380 mg. Half a cup of cooked spinach and one banana each have about 420mg. A baked potato has 610 mg. Depending on any underlying medical conditions such as kidney disease or the use of certain medications, your doctor may recommend that you take potassium in the form of supplements in addition to trying to increase your dietary intake of potassium.
Symptoms of low potassium include muscle cramps, constipation, and heart irregularities. A state of low potassium levels is known as hypokalemia. Hypokalemia may occur with vomiting, diarrhea, and excessive sweating. Certain medications such as diuretics or "water pills" may also cause hypokalemia.
Potassium toxicity or having too much potassium may manifest as abnormal heart rhythms or palpitations which are known as arrhythmias. Muscle weakness and malaise are other symptoms of potassium toxicity. Having too much potassium is also known as hyperkalemia. It is unlikely that a person will have hyperkalemia through diet alone unless there is a history of a medical condition like kidney disease or the use of potassium supplements either orally or intravenously.
Some people may believe that sports drinks are necessary to replete potassium while exercising. In reality, many sports drinks have only 40-90 mg of potassium in an 8-oz. serving. By comparison, a glass of orange juice has about 470 mg. Unless a person is doing very strenuous exercise or has a prolonged exercise session of one hour or more, one is unlikely to require replenishment of potassium stores. In order to ensure that one is getting enough potassium, it is best to eat a variety of different foods, particularly fruits and vegetables which are low calorie sources of potassium.