Potassium - the heart mineral

Everyone knows: calcium is important for the bones, zinc for the skin, iron for the blood, magnesium for the muscles. And potassium? Only a few know that it is one of the vital minerals. It is needed for the function of all body cells. An imbalance in the body has serious consequences - especially for the heart.

Potassium is an important electrolyte in the human organism. It occurs in the body in dissolved form as a positively charged ion, abbreviated as K+. In the periodic system it is in the 1st main group. The mineral regulates the water balance of the cells and contributes to normal muscle function. It influences our sensation of cold and heat by enabling the nerve fibres to transmit impulses. In addition, it activates the carbohydrate metabolism, i.e. it is important for energy production. In interaction with magnesium, potassium ensures the smooth transmission of electrical impulses in the heart. Since the mineral is also involved in the regulation of blood pressure, a look at the potassium level is especially important for hypertension patients. A disturbance increases the risk of damage to the blood vessels. The body needs more potassium during sweaty work and sports. This is because larger amounts are lost during sweating.

Our body cannot produce potassium itself, so it must be taken in through the diet. Potassium is excreted via the kidneys and to a small extent via the intestines. The mineral is contained in almost every food, so a deficiency hardly ever occurs in healthy people. According to the reference values of the German Nutrition Society (DGE), the requirement for adults is about 4,000 mg per day.

Fruits and vegetables that are particularly rich in potassium include tomatoes, mushrooms, carrots, bananas and apricots. The value is even higher for dried fruit. Potassium is found in rye and spelt flour, milk and dairy products as well as in peanuts, hazelnuts, walnuts and almonds. Besides fish, meat also contains potassium. The leaner the meat, the higher the potassium value. There is even potassium in cocoa, so also in chocolate (mainly dark chocolate with a high cocoa content). Mineral water is another source of potassium. However, depending on the type, the values vary and can be rather neglected compared to food. Highly processed foods as well as fats, oils, sugar and white flour are also low in potassium.

Causes of an undersupply (hypokalaemia) are severe potassium losses, for example through vomiting, taking diuretic or laxative medication or chronic diarrhoea. There are also diseases that affect the potassium balance, such as diabetes and leukaemia. In addition, a deficiency can be the result of kidney weakness with increased urine excretion. Interesting: A potassium deficiency can also be caused by stress. Potassium has the ability to return tense nerves to their resting state again and again. Stress and states of exhaustion lead to increased consumption, which causes the potassium level to drop. The symptoms are non-specific and apply to many diseases. This makes diagnosis difficult. The first signs of a potassium deficiency can be intestinal complaints, fatigue, poor concentration, muscle weakness and heart palpitations. Since potassium supports the function of muscles, paralysis can occur in severe cases. The human heart is also a muscle, so cardiac arrhythmias are often the result of hypokalaemia.

With a potassium-rich diet, a slight deficiency can usually be compensated well. Potassium supplements should never be taken on one's own initiative, but only on medical advice, as otherwise an undesirable potassium excess can occur. There is also a risk of interactions with other medicines. To prevent a potassium deficiency, it is important to make sure you drink enough. Optimal amounts are 1.5 to 2 litres of water, fruit and vegetable juice spritzers or herbal tea. Nettle tea provides high amounts of potassium. To avoid an excess, a maximum drinking quantity of 1 - 2 cups daily is recommended.

We usually consume about 5 - 6 g of potassium per day through food. This is harmless if kidney function is intact. However, blood transfusions, burns, hormonal disorders or existing kidney weakness can lead to excess potassium (hyperkalaemia). Elevated levels also occur as a side effect of various medications. This manifests itself, for example, in cramps, muscle twitching, muscle weakness, headaches, fatigue or an increased urge to urinate. Long-term overuse can lead to paralysis and lung failure. In addition, the regulation of blood pressure is disturbed. This leads to high blood pressure, which in turn increases the risk of suffering a stroke. If the hyperkalaemia is chronic, potassium-increasing drugs are discontinued and replaced by others if necessary. In addition, a low-potassium diet is advisable. In the event of an acute increase in potassium levels, immediate measures are necessary, as there is a risk of life-threatening cardiac arrhythmias, including ventricular fibrillation.

Because of its far-reaching consequences, potassium is determined as standard in almost every blood test. The normal value is between 3.5 and about 5.0 mmol/l (millimoles per litre). If the potassium level is below 3.5 mmol/l, it is called hypokalaemia, and if it is above 5.0 mmol/l, it is called hyperkalaemia. Important when taking blood: If the arm is stagnated for too long, unnaturally high values can occur. A urine test also allows the potassium level to be determined. The normal value in urine is between 30 and 100 mmol/24h (collected urine within 24 hours). A value below 20 mmol/l indicates a potassium deficiency.

Potassium ensures that muscles and nerves function. Too low a level is harmful, but so is too high a level. Potassium is particularly important for the heart: on average, the largest muscle in our body contracts 70 times per minute and pumps blood through our body. Without potassium, the proper muscular activity of this organ would be impossible. If you are healthy and eat a balanced diet, elevated or decreased levels are unlikely. Only people with acute or chronic pre-existing conditions need to have their potassium levels checked regularly.