Potassium, along with calcium and sodium, is an electrolyte (mineral salt) important to the human nervous system, muscle function, fluid balance and heart, kidney and adrenal functions. A deficiency of potassium (hypokalemia) can manifest as weakness, fatigue, confusion, heart irregularities, and sometimes problems in muscular coordination. Insufficient potassium can also exaggerate the effects of sodium. The first sign of a potassium deficiency is usually a generalized weakness.
Most people get sufficient potassium in a reasonably healthy diet — one that includes fresh fruits and vegetables and is low in sodium. Mineral imbalances can occur from starvation diets, but more commonly results from excessive fluid loss from sweating, diarrhea, or the use of diuretics and laxatives.
People who exercise heavily, and therefore sweat heavily, have higher potassium needs; they may need to take supplements to balance the electrolyte levels, or to bulk up their menus with high potassium foods.
On the other hand, people who suffer from some diseases, including diabetes and renal (kidney) failure can no longer metabolize minerals properly and need to guard against getting too much in their diet.
Since potassium has not been one of the nutritional values required in food labeling, determining the amount of dietary potassium has been more difficult than, for example, sodium or fat content in foods. This changed in November, 2000; effective in the year 2001, potassium content will be included in the labeling on food packaging.
People without the ordinary potassium requirements — either a need to supplement because of fluid loss, or a need to limit their intake — should consult with their physician or nutritionist to determine their specific needs from each group.
For general guidelines, Duke University Medical Center and the American Kidney Foundation have divided foods into low, moderate and high potassium groups. Some of the more common foods in each category are:
HIGH potassium (more than 225 milligrams per 1/2 c. serving)
These foods would be beneficial to athletes or to others who incur heavy fluid loss. Patients on potassium-restricted diets should avoid them, or eat them sparingly, as advised by their nutritionist.
All meats, poultry and fish are high in potassium.
Apricots (fresh more so than canned)
Oranges and orange juice
Potatoes (can be reduced to moderate by soaking peeled, sliced potatoes overnight before cooking)
MODERATE (125 – 225 mg per serving)
These foods can be a large part of most people’s balanced nutrition plan. Persons restricting their potassium might be cautioned to include no more than one or two servings from this list per day, depending on their medical
Summer squash, including zucchini
LOW potassium (less than 125 mg per serving)
These foods give less electrolyte value per serving for people who need to increase their potassium levels.
They should be a major part of the menu plan for people limiting their intake.
Mandarin oranges, canned