Potassium is an essential mineral found mainly in the intracellular fluid; a small amount occurs in the extracellular fluid. Potassium constitutes 5 percent of the total mineral content of the body. Potassium and sodium help regulate water balance within the body; that is, they help regulate the distribution of fluids on either side of the cell walls.
Potassium is necessary for normal growth, to stimulate nerve impulses for muscle contraction, and to preserve proper alkalinity of the body fluids. It aids in keeping the skin healthy. Potassium assists in the conversion of glucose to glycogen, the form in which glucose can be stored in the liver. It functions in cell metabolism, enzyme reactions, and the synthesis of muscle protein from amino acids in the blood. It stimulates the kidneys to eliminate poisonous body wastes.
Potassium works with sodium to help normalize the heartbeat and nourish the muscular system. It unites with phosphorus to send oxygen to the brain and also functions with calcium in the regulation of neuromuscular activity.
Food sources of potassium include all vegetables, especially green leafy vegetables, oranges, whole grains, sunflower seeds, and mint leaves. Large amounts of potassium are found in potatoes, especially in the peelings, and in bananas.
Potassium is rapidly absorbed from the small intestine. It is excreted mainly through urination and perspiration, and very little is lost in the feces. The kidneys are able to maintain normal serum levels through their ability to filter, secrete, and excrete potassium. Aldosterone, an adrenal hormone, stimulates potassium excretion.
Excessive potassium buildup may result from kidney failure or from severe lack of fluid.
Because sodium and potassium must be in balance, the excessive use of salt depletes the body's conservation of its often scarce potassium supplies. In addition, potassium can be depleted by prolonged diarrhea, excessive sweating, vomiting, and the use of diuretics.
Alcohol and coffee increase the urinary excretion of potassium. Alcohol is a double antagonist since I it also depletes the magnesium reserve. Excessive in-1 take of sugar is also antagonistic towards potassium.
A low blood sugar level is a stressful condition that strains the adrenal glands, causing additional potassium to be lost in the urine while water and salt are I held in the tissues. An adequate supply of magnesium is needed cells.
A Recommended Dietary Allowance for potassium has not been established, but many authorities suggest that between 2000 and 2500 milligrams be included in the diet daily. The amount of potassium in the average American's daily diet has been estimated at 2000 to 6000 milligrams per day, since it is distributed in many different foods.
Deficiency Effects and Symptoms
Excessive urinary losses induced by high salt intake have caused potassium deficiencies to be commonplace. A potassium deficiency can result from an excessive intake of sodium chloride or from an inadequate intake of fruits and vegetables. Refined sugar can cause the urine to become alkaline so that minerals cannot be held in solution. Deficiency can be caused by prolonged intravenous administration of saline, which induces potassium excretion.91 Vomiting, severe malnutrition, and stress, both mental and physical, may also lead to potassium deficiency.
A potassium deficiency may cause nervous disorders, insomnia, constipation, slow and irregular heartbeat, and muscle damage. When a deficiency of potassium impairs glucose metabolism, energy is no longer available to the muscles and they become more or less paralyzed.
When the body is lacking potassium, the sodium content of the heart and muscles increases. Infants suffering from diarrhea may have a potassium deficiency because the passage of the intestinal contents is so rapid that there is decreased absorption of potassium.92 Diabetic patients are often deficient in potassium. Persons suffering from diseases of the digestive tract are frequently found to be potassium-deficient. A person loses potassium when taking water pills or hormone products such as cortisone and aldosterone. Sodium is retained and potassium is excreted when these drugs are administered. Early symptoms of potassium deficiency include general weakness and impairment of neuromuscular function, poor reflexes, and soft, sagging muscles. In adolescents, acne can result; in older persons, dry skin may occur.
Beneficial Effect on Ailments
Potassium has been used to treat cases of high blood pressure which were directly caused by excessive salt intake. Colic in infants has disappeared after injections of potassium chloride. Potassium chloride has also proven effective in treating allergies.
Giving potassium to patients with mild diabetes can reduce blood pressure and blood sugar levels. Since potassium is essential for the transmission of nerve impulses to the brain, it has been effective in the treatment of headache-causing allergies.
Potassium has also been used in the treatment of diarrhea in infant and adults. Therapeutic doses of potassium are sometimes used to slow the heartbeat in cases of severe injury, such as burns.