Potassium is an essential mineral whose ions are vital for the functioning of all living cells. It accumulates in plant cells, meaning that many fresh vegetables and fruits — most famously bananas — are rich in it. Dissolved potassium is also found in sea vegetables such as kelp, bladderwrack and kombu, since seawater is approximately 0.04 percent potassium by weight.
While most people are aware on some level that potassium is important, few people really understand what it does for us. This article takes a closer look at the roles of potassium in our bodies and reveals how much of it our bodies need per day to function properly.
The four main roles of potassium
Regulates water balance — One of potassium’s biggest roles in our bodies is to regulate the amount of sodium entering and exiting our cells, thereby controlling the amount of fluid we retain or excrete. This maintains the body’s pH levels, which ensures that our cellular processes proceed at an appropriate rate. People who are deficient in potassium often suffer from fluid retention, which can cause edema, an unpleasant condition that leads to swelling and water-related weight gain.
Aids biochemical processes — Potassium plays an important role in energy metabolism and cellular biochemical reactions. It helps us synthesize protein from amino acids in cells (thus helping us to grow muscle and build cells), and also helps us convert glucose to glycogen for storage in the liver as a future supply of energy. For these reasons, potassium-rich foods tend to be a popular choice with bodybuilders and athletes.
Maintains electrolyte and acid-base balance — Potassium is a positively charged electrolyte, and its presence (or absence) directly affects the actions of other electrolytes such as calcium or sodium in our bodies. For example, a deficiency in potassium and an excess in calcium can result in kidney stones, since calcium ions — without being balanced by potassium ions — can be excreted by our kidneys into our urine. Moreover, potassium ions bind themselves to negatively charged bicarbonate ions, which creates a buffer that regulates our bodies’ acid-base balance. A body with an acidic pH is, of course, a breeding ground for disease.
Boosts nervous system function — Our bodies use potassium ions to conduct electrical impulses along muscle and nerve cells. These impulses — which are essentially electrical currents — are what keep the heart pumping and the muscles contracting. Without potassium (and other minerals such as calcium and sodium), we could not transport signals from our nervous systems to elsewhere in our bodies, resulting in irregular heartbeats and heart arrhythmias. For this reason, potassium is also needed for a healthy cardiovascular system.
How much potassium do we need?
The recommended daily allowance of potassium for adult men and women (including pregnant women) is 4,700 milligrams per day, while children need 4,500 milligrams of it per day. Though potassium deficiencies are not as widespread as magnesium or iodine deficiencies, they are becoming more common (especially in the United States) and can result in muscle cramps, loss of appetite, fatigue, weakness and nausea. People who consume a diet rich in organic whole foods, however, usually do not have to worry about a deficiency in potassium since natural produce contains it in abundance.
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