It is important for your body to maintain consistent levels of potassium in the blood. If potassium levels become too low or too high, serious problems with heart rhythms can result. Older adults can be at risk of low levels of potassium in the blood because of medications, diarrhea or vomiting, or inadequate diet among other reasons. Laxatives and some diuretics (water pills) are the most common medication causes. Besides prescription supplements, you can get potassium from eating bananas, oranges, and cucumbers. Your pharmacist can give you advice to help you keep potassium levels within range. Mark Mercure, Geriatric Pharmacist