Function: Potassium balances water and acid in the blood and body tissues. It is also important for building muscle and metabolizing protein and carbohydrates.

Sources: Fish, meat, peas, lima beans, potatoes, leafy green vegetables, citrus fruits (especially skins), bananas, apricots, melons, and dried fruits are all great sources of potassium.

Recommended daily intake: Although there is no RDA, between 2 and 2.5 grams of potassium per day is sufficient. People with chronic diseases or seniors may develop potassium deficiency, known as hypokalemia, which can result in fatigue, slow reflexes, muscles weakness and dry skin. Diarrhea, vomiting, and use of diuretic and cortisone medications can also lead to deficiency. If potassium levels are depleted quickly, heart problems could occur. If not replenished quickly, heart failure and death can result. Too much potassium can lead to too much potassium in the blood, known as hyperkalemia. People with kidney problems or severe infection may suffer from this.