Potassium is the principal cation in intracellular fluid and functions in acid-base balance, regulation of osmotic pressure, conduction of nerve impulse, muscle contraction particularly the cardiac muscle, cell membrane function and Na⁺/K⁺-ATPase.

Potassium is the principal cation in the intracellular fluid, which means that the main source of potassium is cellular material that we consume in food. Therefore, the deficit caused by low potassium diet is extremely rare and occurs when there is very little protein calories.

The average content of potassium in the body is 140 grams.

Physiological role of potassium

Potassium regulates water and salt metabolism in the cell, osmotic pressure, acid-base balance, normalizes heartbeat, participate in the surrender of nerve impulses muscles, increases removal of sodium and water from the body and activates certain enzymes.

In addition, potassium plays an important role in protein biosynthesis and the conversion of blood sugar into glycogen. Activates a number of enzymes, especially those involved in energy production. Stimulates normal intestinal movements.

Metabolism

Potassium is easily absorbed in the small intestine. Potassium reabsorption is passive and does not require special arrangements. Potassium comes with extracellular fluid in all parts of the body and can have a significant impact on the function of certain organs, especially the depolarization and contraction of the heart. The main organ which control potassium level is kidney, but it cannot effectively retain K⁺ in the body as it can sodium(Na⁺). Sodium is retained at the expense of potassium and aldosterone act on it. So in normal subjects there is a mandatory loss of potassium, which is about 16 mg per day. Potassium is removed from the body in urine and sweat.

Food sources of potassium

The main sources of potassium are dried apricots, potatoes, meat, fish, tomatoes, beets, figs, green onions, broccoli, chokeberry, grape, cherry, plum, pear, pumpkin, soy, shellfish, beans, wheat flour, hazelnuts, cereals, milk , coffee, tea, semenasta food, pistachios, avocados, peanuts, ham, melon, banana, orange, green peas, spinach, barley, beef, chocolate.

Recommended daily allowance

The daily is recommended intake of at least 2000 mg of potassium. The most adults, however, consume from 800 to 1500 milligrams per day. In the UK recommended daily amount of potassium is 3500 milligrams, and in Australia from 1950 to 5460 milligrams.

Potassium deficiency

A lack of potassium in the body can occur due to excessive colic ingested sodium, heavy sweating, frequent vomiting, diarrhea, and then due to surgical operations on the intestine, inflammation, injury, diabetes, high aldosterone excretion, chronic diarrhoea that limit the absorption of potassium, disordered action of hormones adrenals, intense vomiting, influenza, intestinal diseases, anemia, kidney disease, heart, through prolonged fasting, therapeutic starvation, inadequate diet, anorexia, alcoholism, and cystic fibrosis.

Symptoms include general body weakness, fatigue, loss of appetite, sleepiness, vomiting, abdominal pain, arterial hypotonia, cardiac rhythm disturbance, muscle weakness, paralysis, loss of appetite, high blood pressure, thirst, confusion and in severe cases coma. Muscle spasms, tetany and cardiac arrhythmias can also occur due to insufficient amounts of potassium.

Consequences of potassium deficiency are adynamia, sallow of skin and increased arousal of the nervous system.

Overdose

Potassium intake of amounts greater than 18 grams per day can cause muscle weakness, cardiac arrhythmias, low blood pressure, mental confusion and possible myocardial infarction.

With normal diet, there cannot be excessive intake of potassium, but potassium excess is due hypofunction of adrenal cortex, impaired secretary function of the kidneys, the use of aldosterone antagonists, acidosis, shock of serious injuries.

Potassium in medicine

Potassium is one of the most commonly attributed of minerals. It is used in situations where there is a loss of potassium from the body, such as diuretic therapy. In addition, potassium is used in disordered heart rhythm, treatment of glucocorticoid hormones, high blood pressure and various heart disease (myocardial infarction, etc.) for the prevention of kidney stones in the kidney. In addition, potassium is used to treat fatigue and changes in mood in the early stages of menopause. It is also used to treat allergies, headaches, diarrhoea.

Potassium supplements are consumed immediately after meals with plenty of water. Potassium is also used by athletes because they lose a large amount of potassium through sweating. Potassium tablets should not be allowed to consume with alcohol because there is irritation of the stomach.

People who are in the process of dehydration, cramps, having ulcers or kidney disease should not be allowed to consume potassium pills without consulting a doctor.

References

Aburto N.J., et al., 2013, “Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses,” BMJ; 348:f1378. [Web Reference]

Aaron K.J. and Sanders P.W., 2013, “Role of dietary salt and potassium intake in cardiovascular health and disease: a review of the evidence,” Mayo Clinic Proceedings. Elsevier; 88(9): [Web Reference]

Gropper S.S. and Smith J.L., 2012, “Advanced nutrition and human metabolism,” Cengage Learning. [Web Reference]

Malhotra V.K., 1998, “Biochemistry for Students. 10^th Ed,” Jaypee Brothers Medical Publishers (P) Ltd, New Delhi, India. [Web Reference]

Soetan K.O., Olaiya C. O. and Oyewole O.E., 2010, “The importance of mineral elements for humans, domestic animals and plants-A review,” African Journal of Food Science; 4(5): 200-222. [Web Reference]