Potassium . Name with which Humphrey Davy baptized it upon discovering it in 1807, being the first metallic element isolated by electrolysis, in his case the potassium hydroxide KOH , compound from whose Latin name, Kalĭum, comes the chemical symbol of potassium.

It is a silver-white alkaline metal, which is abundant in nature in elements related to salt water and other minerals. It oxidizes rapidly in air, is highly reactive, especially in water, and chemically resembles sodium.

It constitutes the order of 2.4% by weight of the earth’s crust, being the seventh most abundant. Due to its solubility, it is very difficult to obtain pure metal from its minerals. Even so, in ancient sea beds and lakes there are large deposits of potassium minerals (carnalite, langbeinite, polyhalite and silvin) in which the extraction of the metal and its salts is economically viable.


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  • 1 Features
  • 2 Function
  • 3 Natural sources
  • 4 Toxicity
    • 1 Causes
  • 5 Sources


It is the mineral that appears in greater quantity in the body after calcium and phosphorus and that always appears associated with sodium . This macro mineral maintains normal pressure inside and outside the cells, regulates the water balance in the body, reduces the negative effects of excess sodium and participates in the contraction and relaxation mechanism of the muscles . 97% of potassium is found intracellularly and the remaining 3% extracellularly.

Potassium is present in: grains , meats , vegetables , fruits and legumes.

Approximately 90% of the ingested potassium is absorbed in the small intestine and is eliminated through the urine , the excessive consumption of coffee , tea , alcohol and / or sugar increases the loss of it.

The symptoms that indicate its absence are immediate, and are shown as: muscle weakness, nausea , vomiting , irritability and even cardiac irregularity.

Conversely, kidney failure and the non-intake of fluids, generates excesses of this macromineral in the blood .

Potassium is the major cation in the intracellular fluid of the human body. It is involved in maintaining the normal balance of water, the osmotic balance between cells and interstitial fluid, and the acid-base balance, determined by the body’s pH . Potassium is also involved in muscle contraction and the regulation of neuromuscular activity, by participating in the transmission of the nerve impulse through the action potentials of the human organism.


Potassium is an elemental mineral in our body, because it performs basic functions such as regulating water inside and outside of cells . This occupation is carried out in conjunction with sodium. The most important functions are:

  • Essential for the correct growth of the organism.
  • It is part of the bones.
  • Participates in the osmotic balance: concentration of substances inside and outside the cells.
  • It intervenes in the production of proteinsfrom its main components that are amino acids .
  • It intervenes in the metabolism of carbohydrates.
  • It collaborates in the permeability of the membranes.
  • It is essential for the synthesis of muscles.
  • Participates in chemical reactions.
  • It intervenes in the nervous transmission.
  • Participates in muscle contraction.

Natural sources

Foods rich in potassium

The most potassium-rich foods are fruits and vegetables, especially green leafy ones. Among the fruits, banana or bananas, grapes , oranges , prunes, dates and melon stand out . Likewise, we find a large amount of potassium in legumes, seeds and meats. Nuts such as almonds , walnuts , hazelnuts , etc., are also an important source of potassium along with cocoa .


High Potassium

The body needs an adequate amount of potassium for the heart and other muscles to function properly. However, too much potassium in the blood can cause dangerous, and possibly life-threatening, changes in heart rhythm. Hyperkalemia is called elevated serum potassium (in plasma). Hyperkalemia occurs when potassium intake exceeds the kidney’s ability to pass urine.

The causes of hyperkalemia are due to excessive potassium intake, decreased potassium excretion, or when intracellular potassium passes into the extracellular space. The most common cause is due to decreased excretion by the kidney. Simply consuming too much potassium does not cause toxicity in healthy individuals. Normally, for hyperkalemia to occur, the individual has different disorders at the same time.


  • Excessive intake: As we mentioned previously, by itself, it rarely causes hyperkalemia because the mechanisms of renal excretion are very efficient. In general, an increased intake of potassium contributes to hyperkalemia in people who have impaired renal excretion when they follow low sodium and high potassium (potassium salts) diets and if they ingest potassium supplements even in low amounts.
  • Excess contribution of endogenous origin; given by the body itself when an acute and massive destruction of tissuesreleases cells of a significant amount of potassium into the extracellular environment. It occurs in burns , crushing of limbs, hemolysis, tumor lysis syndrome due to chemotherapy and severe gastrointestinal bleeding.
  • Decreased excretion: due to acute or chronic kidney failure, Addison’s disease, hyperaldosteronism, kidney transplant, diuretics, cyclosporins, lithium, etc.
  • Transncelular potassium redistribution: occurs in acidosis, intense muscular exercise, untreated type I diabetes, by medications (beta-blockers, digitalis, fluorides , succinylcholine, cyanides ) and familial periodic paralysis.


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