Potassium

Potassium is a mineral that helps the kidneys function normally. It also plays a role in cardiac, skeletal, and smooth muscle contraction, making it an important nutrient for normal heart function. Recent studies have suggested that potassium helps lower blood pressure, and that it can help reduce the risk of death from an acute heart attack when administered by a health care provider along with insulin and glucose. If you take in too much potassium in your diet, you run the risk of getting hyperkalemia (having too much potassium in the blood). If you don't take in enough, you run the risk of getting hypokalemia (not having enough potassium in the blood).

For most people a healthy diet rich in vegetables and fruits is a safe way to get the amount of potassium you need. The elderly are at a high risk for hyperkalemia due to the decreased kidney function that occurs naturally as you age. Older people should be careful when taking any medication, because they can affect potassium levels in the body. Talk with your health care provider before taking potassium or any supplement.

Uses

The most important use of potassium is to treat the symptoms of hypokalemia, which include weakness, lack of energy, stomach disturbances, an irregular heartbeat, and an abnormal EKG (electrocardiogram, a test that measures heart function).

Under a health care provider's supervision, potassium can also be used to lower blood pressure, prevent stroke, treat muscle weakness and diabetes mellitus, and help prevent death from an acute heart attack.

Dietary Sources

The best dietary sources of potassium are fresh unprocessed foods, including meats, vegetables (especially potatoes), fruits (especially avocados), and citrus juices (such as orange juice). Most of our potassium needs can be met by eating a varied diet with adequate intake of milk, meats, cereals, vegetables, and fruits.

Other Forms

There are several potassium supplements on the market, including potassium acetate, potassium bicarbonate and potassium citrate effervescent, potassium chloride, and potassium gluconate. Potassium can also be found in multivitamins.

How to Take It

You should not take a potassium supplement other than what's in a multivitamin unless your health care provider instructs you to do so. As with all medications and supplements, check with a health care provider before giving potassium supplements to a child. The average potassium intake estimated by the National Research Council is as follows. This amount is most likely provided by your daily diet.

• Infants: 780 mg a day
• Children: 1,600 mg a day
• Adults: 3,500 mg a day

There is no recommended increased intake of potassium during pregnancy and nursing.

Precautions

If you have kidney problems, you should not take potassium supplements unless told to do so by your health care provider. If you are elderly, take potassium supplements under the supervision of your health care provider, because of decreased kidney function with age.

Possible Interactions

Nonsteroidal anti-inflammatory drugs (such as ibuprofen) may raise blood levels of potassium. ACE inhibitors (such as captopril, enalapril, and lisinopril) can increase blood levels of potassium, particularly when taken with salt substitutes or potassium-sparing diuretics (such as spironolactone, triamterene, or amiloride). Heparin, cyclosporine, trimethoprim, pentamidine and beta-blockers (such as metoprolol and propranolol that are used to treat high blood pressure) may also elevate blood levels of potassium. Consult your health care provider before supplementing with potassium if you are taking any of these medications.

Corticosteroids, amphotericin B, antacids, loop diuretics (such as furosemide and bumetanide), and thiazide diuretics (such as hydrochlorothiazide) lower potassium levels. Insulin also reduces the level of potassium in the blood.

Lower blood levels of potassium increase the likelihood of toxic effects from digoxin. Consult your health care provider to determine if you should take potassium supplements while on this medication.

Supporting Research

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Brancati FL, Appel LJ, Seidler AJ, Whelton PK. Effect of potassium supplementation on blood pressure in African Americans on a low-potassium diet. Arch Intern Med. 1996;156:61–72.

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