Potassium

Most people who eat a healthy diet should get enough potassium naturally. However, many Americans don't. While the typical American diet, which is high in sodium-containing processed foods and low in fruits and vegetables, contains about two times more sodium than potassium, many health experts recommend taking in at least five times more potassium than sodium. So the average U.S. intake of potassium is lower than it should be. 

Potassium is especially important in regulating the activity of muscles and nerves. The frequency and degree to which our muscles contract, and the degree to which our nerves become excitable, both depend heavily on the presence of potassium in the right amount.

Potassium, sodium and chloride comprise the electrolyte family of minerals. Called electrolytes because they conduct electricity when dissolved in water, these minerals work together closely. About 95% of the potassium in the body is stored within cells, while sodium and chloride are predominantly located outside the cell.

Potassium plays an important role in muscle contraction and nerve transmission. Many of our muscle and nerve cells have specialized channels for moving potassium in and out of the cell. Sometimes potassium moves freely in and out, and sometimes a special energy-driven pump is required. When the movement of potassium is blocked, or when potassium is deficient in the diet, activity of both muscles and nerves can become compromised.

Potassium deficiencies are more common in people who use certain medicines, such as diuretics and certain birth control pills, have physically demanding jobs, are athletes, have health conditions that affect their digestive absorption, such as Crohn's disease or chronic diarrhea, have an eating disorder, smoke, abuse alcohol or drugs, have muscle weakness.

Potassium losses from cooking of high-potassium foods can be significant.

Potassium is known to decrease the excretion of calcium. As a result, increasing the amount of potassium-containing foods in your diet may be helpful in maintaining the density and strength of your bones.

With a balanced diet (rich in potassium) you can prevent these disease: atherosclerosis, cataracts, dehydration, diabetes, hepatitis, high blood pressure, osteoporosis. 

Dietary reference intake

Infants 400-700 mg/day

Children 3000-4500 mg/day

Adolescents 4700 mg/day

Adults 4700 mg/day

Pregnant 4700 mg/day

Lactating 5100 mg/day

Potassium content of selected foods

Swiss chard, cooked, 1 cup (960 mg)

Lima beans, cooked, 1 cup (955 mg)

Potatoes, baked, 1 (926 mg)

Soybeans, cooked, 1 cup (886 mg)

Spinach, cooked, 1 cup (839 mg)

Papaya, 1 (782 mg)

Beets, 1 cup raw (442 mg)

Tomatoes, raw, 1 cup (427 mg)

Broccoli, raw, 1 cup (288 mg)

Lettuce, raw, 2 cups (263 mg)

Banana, 1 (422 mg)

Avocado, 1 (689 mg) 

Milk, 1 cup (382 mg)

Deficiency

Weakness

Confusion

Fatigue

Heart disturbance

Irritability

Decrease in glycogen (for athletes)

Toxicity

Nausea

Vomiting

Diarrhea

Ulcers