Potassium is a nutrient that gets less public attention than it deserves. Most nutrition labels on food do not include potassium values because food labeling laws do not require it. Unlike its “bad boy” cousin sodium, potassium is much too low in the diets of most Americans. National surveys estimate that 97 percent of Americans consume less than the current recommendation. Most of us consume just more than half the recommended intake, despite potassium’s potential to deliver great health benefits.

QUESTION: What are the potential health benefits of potassium?

ANSWER: Most of the attention that potassium gets is related to its ability to help lower blood pressure. Potassium is especially effective at lowering blood pressure in people whose high blood pressure (hypertension) is increased by salt, sometimes called sodium-sensitive hypertension. Potassium counteracts sodium’s effect on blood pressure, and some research indicates sodium has relatively little effect on blood pressure when potassium recommendations are met.

High blood pressure is associated with increased risk of heart disease, stroke and kidney disease. Studies evaluating contributors to cardiovascular mortality place hypertension at the top of the list, followed, in order, by being overweight or obese, physical inactivity, high LDL cholesterol, smoking and high dietary salt. Since most adults will have hypertension at some point in their lives, increasing potassium intake has the potential for a major impact on controlling blood pressure and reducing related diseases.

As potassium intake goes up, the risk of stroke goes down. This may be due partly to potassium’s impact on reducing blood pressure, but many of the fruits and vegetables that provide potassium also have other beneficial components, such as antioxidants, that can have beneficial effects separate from potassium.

Potassium also contributes to bone health. Bones depend on many factors in the diet, but food high in potassium generally helps the body hold onto calcium better, which helps to prevent bone loss.

Adequate potassium can benefit kidney health and even help to slow the progression of some types of kidney disease. Those with impaired kidney function, however, need to follow medical advice that may require limiting potassium intake.

Q: How much potassium is recommended?

A: The Institute of Medicine recommends that adults consume 4,700 milligrams of potassium in the daily diet. Obtaining this amount of potassium is difficult for most people consuming typical U.S. food patterns.

Q: What are good food sources of potassium?

A: Food high in potassium (in decreasing order of potassium per common serving) includes potatoes, prunes, carrots, most leafy greens, beans, tomato juice and sauces, yogurt, sweet potatoes, orange juice and bananas. Most of the potassium in the American diet comes from milk, coffee, chicken, beef, citrus juices and potatoes. Yes, coffee! A typical 8-ounce cup provides more than 100 milligrams of potassium.

Q: Are potassium supplements a good way to meet potassium needs?

A: In general, it is best to obtain potassium from food. High-potassium food tends to provide many other health-promoting components. Potassium supplements can be dangerous for some people, so it is best to obtain medical guidance before taking potassium.

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Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services.