Every cell in your body requires potassium to function. It keeps the fluids and minerals in and around cells balanced and helps cells maintain their electrical charge. This basic activity allows your heart to beat regularly, your nerves to transmit impulses and your muscles to contract smoothly. The mineral occurs in a variety of foods ranging from meat, poultry, fish, milk and yogurt to nuts, seeds, vegetables and fruits. Bananas and kiwifruit are both good sources of potassium.
Bananas are considered a good source of potassium because they supply at least 10 percent of the daily value per serving. Because most people consume the entire fruit in one sitting, one average-sized banana constitutes a single serving. For 105 calories, a medium-sized banana provides about 420 milligrams of potassium, or 12 percent of the daily value. For an additional 15 calories, a slightly larger banana delivers nearly 490 milligrams of potassium, or 14 percent of the daily value. Very small bananas aren’t necessarily a good source of potassium, however. According to the U.S. Department of Agriculture, an extra-small banana will give you about 70 calories and 290 milligrams of potassium, or just 8 percent of the daily value.
Relatively small in size and low in calories, it takes two average-sized kiwifruits to make a single serving. Two green kiwis provide just over 80 calories and 430 milligrams of potassium, or 12 percent of the daily value -- about the same amount as an average-sized banana. According to the USDA, gold-fleshed kiwifruit is slightly higher in potassium than the green variety. For about 100 calories, two gold kiwis supply just over 540 milligrams of potassium, or 16 percent of the daily value. One extra-large banana also delivers 16 percent of the daily value for potassium, but it also contains 25 percent more calories than a serving of gold kiwifruit.
Although a serving of bananas is about 20 percent lower in potassium than a serving of gold kiwis, bananas are actually higher in potassium, ounce for ounce, than both types of kiwifruit. According to USDA data, a 3.5-ounce serving of banana -- about the equivalent of a small-sized fruit -- has 89 calories and 358 milligrams of potassium, whereas a 3.5-ounce serving of gold kiwifruit, or slightly more than one fruit, has 60 calories and 316 milligrams of potassium. Green kiwis provide about the same amount of calories and potassium as gold kiwis.
Potassium is a major mineral, meaning that -- compared to trace minerals such as iron and zinc -- your body needs a relatively large amount each day to avoid deficiency. To buffer the effects of sodium and promote normal blood pressure levels, the Institute of Medicine of the National Academies recommends that healthy adults consume at least 4,700 milligrams of potassium a day. According to the Linus Pauling Institute at Oregon State University, most men in the United States get just over half the recommended amount, while most women get less than half. Including both kiwifruit and bananas in your diet is a good way to boost your potassium intake.
Articles For Your Diet
- MedlinePlus Medical Encyclopedia: Potassium In Diet
- Linus Pauling Institute at Oregon State University: Potassium
- Institute of Medicine of the National Academies: Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate
- USDA Nutrient Data Laboratory: Bananas, Raw
- USDA Nutrient Data Laboratory: Kiwifruit, Green, Raw
- USDA Nutrient Data Laboratory: Kiwifruit, Gold, Raw
- Wellness Foods A to Z; Sheldon Margen, M.D., et al.
- Half kiwi and banana image by Benko Zsolt from Fotolia.com