Apple Valley, CA
760-242-1234

What is potassium?

Potassium is an essential mineral that falls into the group of nutrients called electrolytes. (The other electrolytes are sodium and chloride.) These substances are instrumental in conducting electrical impulses within the body. They are also essential in maintaining the body's normal fluid and chemical balances.

Most of the body's potassium is concentrated in the intracellular fluid inside cells, but small amounts also circulate in the plasma and other body fluids.

Why is potassium important to nutrition?

Potassium, along with the other electrolytes, regulates the movement of water in and out of cells. The electrolytes also control the balance of acids and bases in body fluids and cells. If the balance of water and electrolytes or acids and bases is disturbed, metabolic functions are upset. Balance is a key concept in maintaining these relationships; too much potassium can be as damaging as too little.

Although most of the body's potassium is located in the intracellular fluids, the small amount outside the cells performs a number of vital functions. For example, potassium is essential for the proper working of muscle cells, including those in the heart. (Both too much and too little potassium disrupts heart function.) Potassium also plays a role in the transmission of nerve impulses and helps release energy from the carbohydrates, proteins, and fats that are consumed in the diet.

In recent years, several leading heart researchers have studied the possible role of potassium in protecting against cardiovascular diseases. Population studies have found that people who consume a diet high in high-potassium foods (fresh fruits and vegetables, grains, legumes, and milk)

have a reduced risk of heart attacks and strokes. The precise manner in which potassium may prevent these diseases is unknown, but the American Heart Association recommends that a prudent diet include a variety of high-potassium foods.

How much potassium do I need?

The Recommended Dietary Allowances (RDAs) for potassium have not been established, but in its 1989 revised dietary guidelines, the Food and Nutrition Board of the National Academy of Sciences estimated the following (in milligrams) as safe and adequate daily intakes:

• 500 for babies up to 5 months of age.
• 700 for babies 6 to 11 months of age.
• 1,000 for babies 12 to 23 months of age.
• 1,400 for children ages 2 to 5 years.
• 1,600 for children ages 6 to 9 years.
• 2,000 for all persons ages10 years and older.

Since potassium is an essential component of all living cells, it is found in varying amounts in most foods. Thus, a diet that includes a variety of foods from the four basic food groups (milk and dairy products, vegetables and fruits, grains and starches, and meat, legumes, and other high-protein foods) provide adequate amounts of potassium.

What happens if I don't get enough potassium?
Most potassium deficiencies result from excessive excretion through either the kidneys or gastrointestinal tract. Prolonged vomiting, severe diarrhea, or chronic laxative abuse can deplete the body's potassium reserves. Similarly, prolonged use of diuretics (water pills), such as in the treatment of high blood pressure, can result in excessive loss of potassium in the urine.

A potassium deficiency is referred to as hypokalemia. This serious electrolyte imbalance may lead to abnormal heart rhythms, muscular weakness, lethargy, kidney failure, and, in severe cases, even death.

What happens if I get too much potassium?
Excessive potassium (hyperkalemia) can be as serious as a deficiency. The kidneys can handle moderate overdoses by increasing the amount of potassium excreted in the urine. But consuming a very large amount of potassium can overwhelm the body and result in cardiac arrest. More moderate hyperkalemia can cause irregular heartbeats, muscle spasms, tremor, and paralysis.

Should I take a potassium supplement?
An ordinary diet provides all the potassium a person needs; thus, supplements normally are not needed. In fact, for most people, potassium supplements can be dangerous. Supplements may be prescribed, however, for some people who must take diuretics for high blood pressure, since these drugs can deplete the body's stores of potassium. Even so, potassium supplements should be taken only under a doctor's supervision.

Printer Friendly Page