Potassium is a mineral salt, also known as an electrolyte, that contributes to the healthy function of the muscular system, including the heart, as well as the nervous and digestive systems. Your body does not make potassium naturally and you must get it from foods or through supplementation. Bananas are a rich source of dietary potassium, and eating bananas will increase your potassium levels, but it will not cause your body to create more potassium.
Blood Potassium Levels
Your body stores the majority of the potassium in your body inside your cells, and a certain amount also resides in your blood. In healthy individuals, the normal potassium range is between 3.7 and 5.2 mEq/L. Potassium dissolves in water, and your levels fluctuate throughout the day depending on how much you urinate or sweat. The kidneys control potassium levels in your blood, and abnormal blood potassium levels could be a sign of kidney disease.
Daily Potassium Requirements
To maintain blood potassium levels, an adult should consume at least 2,000 mg of potassium from either supplements, dietary sources or a combination of both, according to the University of Maryland Medical Center. The Institute of Medicine's recommended dietary allowance is 4,700 mg per day.
Potassium in Bananas
The amount of potassium in bananas varies by the size of the fruit. A medium fruit has approximately 451 mg of potassium. When you eat the banana, you digest it in your intestines and absorb the nutrients, including the potassium, into your bloodstream. Your body absorbs some of the potassium into your cells and leaves a portion in your blood. If the banana raises your blood levels higher than the maximum level, your kidneys will excrete the excess potassium in your urine.
Other Food Sources
Although bananas are high in potassium, other foods have just as much potassium or more. For example, 1/2 medium avocado has 550 mg of potassium, and black beans have as much as 801 mg per cup. Eight ounces of orange juice has 474 mg, and 6 oz. of tomato juice has 658 mg. You can also get potassium from meat sources such as ground beef with 205 mg, flounder with 292 mg and chicken with 195 mg.
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