Potassium: Function & Diseases

As a positively charged ion (cation), potassium is one of the essential minerals and is essential for cell and nerve function.

Mode of action of potassium

A blood test of potassium levels is used by physicians to further diagnose various diseases. Potassium, along with sodium as its counterpart, is one of the most important electrolytes in the human body, which are crucial for maintaining the so-called osmotic pressure in cells. Thus, potassium as an electrolyte also serves to regulate the water balance, among other things. Potassium is found almost exclusively within the cells. The concentration gradient between the inside and outside of the cell is maintained for potassium, as for sodium, at the cell wall with the aid of a so-called ion pump (here sodium-potassium pump). This creates an electrical voltage, which is a prerequisite for the transmission of information between the cells. Therefore potassium, together with sodium and calcium, plays an essential role in the excitability of nerve and muscle cells, for example those of the heart. The body of an adult contains about 170 g of potassium.

Importance

Adults need about 2g of potassium daily. Because the mineral is found in many foods, a balanced diet usually meets the requirement. The body itself keeps potassium levels within narrow limits, since rising or falling potassium levels can quickly lead to impulse disorders of the muscles and nerves, which then can no longer contract properly. The hormone aldosterone is responsible for regulating potassium levels. If the potassium level rises, the body secretes more of this hormone, as it stimulates the kidneys to excrete more potassium. But potassium is not only important for muscle and nerve functions, it also regulates the fluid balance within the cells. In addition, it plays a role in the production of various proteins, regulates blood pressure and heartbeat, and is involved in carbohydrate metabolism and thus in energy production. A potassium deficiency usually results from increased fluid loss. Since potassium levels are strongly linked to sodium levels, an increased intake of sodium automatically leads to a higher excretion of potassium. A diet high in salt can therefore lead to a deficiency of potassium. Certain medications such as laxatives and diuretics can also lead to a deficiency. Vomiting and diarrhea, alcoholism, eating disorders such as bulimia and anorexia, certain intestinal diseases, and reduced fluid intake also often lead to a deficiency. Symptoms of this are usually fatigue, reduced performance, cramps, muscle pain, circulatory problems and cardiac arrhythmias. A potassium deficiency can easily be counteracted by a change in diet. Athletes in particular should make sure that their intake is sufficient, as they lose more potassium through sweating. Endurance athletes or athletes with intensive training are particularly affected. A deficiency can lead to serious drops in performance and muscle complaints. More extreme, however, are the effects of an excess of potassium, as it can quickly lead to life-threatening cardiac arrhythmias with ventricular fibrillation and even death. Especially in bodybuilding, it has already come to some deaths by taking appropriate preparations, which are to provide for a dehydration before a competition.

Occurrence in food

Foods with a high proportion of potassium are first and foremost plant foods such as fruits and vegetables, cereals and nuts. Wheat germ, avocados and bananas are particularly high in potassium. When preparing vegetables, care should be taken to ensure that potassium is transferred to the water during cooking. If this is not used further, the potassium is also lost.