The recommended amount of potassium a person needs is 4,700 milligrams per day for people over age 18, according to WebMD. Other factors, such age or breastfeeding, may increase or decrease the daily amount needed.
In general, children under age 14 require less potassium, starting at 4,500 mg a day and decreasing with age, according to WebMD. When a woman is breastfeeding, the recommended intake climbs to 5,100 mg each day. Potassium can be found in a variety of foods, including avocados, bananas, leafy green vegetables, potatoes and milk. If taking a supplement, it is recommended that people take it with a full glass of water or juice.