It is the mineral that appears in greater amounts in the body after calcium and phosphorus and always appears associated with sodium.
This macromineral normal pressure maintained inside and outside of cells, regulates the water balance in the body decreases the adverse effects of excess sodium and participates in the mechanism of contraction and relaxation of the muscles (especially in cardiac patients).
Potassium 97% is 3% intracellularly and extracellularly remaining.
Potassium is found in grains, meats, vegetables, fruits and legumes.
Approximately 90% of potassium intake is absorbed in the small intestine and eliminated through urine.
Excessive consumption of coffee, tea, alcohol and / or sugar increases this loss through the urine.
As a result of strict calorie diets, vomiting, diarrhea, increased sweating, excessive losses and burns diuretics, originates mineral deficiency in the body.
Symptoms indicating their absence are immediate, and are shown as: muscle weakness, nausea, vomiting, irritability and even cardiac irregularities.
Conversely, renal failure and no fluid intake, this macromineral generates excess in the blood.
The daily requirement of potassium is close to 3.5 g / day
Potassium is an essential mineral in our diet. Together with sodium and chlorine belongs to the family of electrolytes. The term electrolyte means any substance that dissociates into ions (charged particles) when dissolved in water and conduct electricity. About 95% of potassium is deposited in the cells, while the sodium and chlorine are located mainly you were thereof. Potassium is the cation (positively charged ion) is most abundant in the intracellular fluid (within the cells.), While sodium is the main cation in extracellular fluids.
Potassium is particularly important in the regulation of the activity of the muscles and nerves.
It is easily absorbed in the small intestine. About 90% of the potassium intake is excreted in urine. The remainder is excreted in faeces and sweat.
The hormone aldosterone is who stimulates potassium excretion by the kidneys to maintain normal levels of it in our body. The potassium along with sodium, regulate fluid and electrolyte balance, because the cations are most abundant intracellular and extracellular fluid respectively.
Potassium plays an important role in the body. Together with sodium, regulate the balance of water and acid-base in blood and tissues. Potassium concentrations are 30 times greater in the interior of cells while sodium concentrations are 10 times lower. This difference creates a gradient of concentrations as known electrochemical membrane potential. This causes the sodium to move inside the cell and the potassium moves out of the same generating a membrane electric potential. This helps generate electric potential muscle contractions, nerve impulses and regulating heart function.
Many enzymes require the presence of potassium to activate. Among them, the enzyme pyruvate kinase, important in the metabolism of carbohydrates. Thus, it is involved in the storage of carbohydrates acting cosmbustible for muscles. It is essential in the synthesis of proteins and nucleic acids.
Natural Sources of Potassium
Foods rich in potassium are fruits and vegetables, especially greens. Within the fruit stand banana or bananas, grapes, oranges, prunes, dates and melons. Also found lots of potassium in vegetables, seeds and meat. Nuts such as almonds, walnuts, hazelnuts, etc.., Are also a major source of potassium with cocoa.
The following table mentions the number of milligrams (mg) of potassium present in a portion of food;
It is called hypokalemia hypokalemia or a disorder in fluid balance in our bodies characterized by low levels of potassium in the blood. There are different causes that trigger potassium deficiency, such as:
Inadequate intake of potassium in diets low in potassium alone is rarely hypokalemia. Usually occurs in older people who can not eat or swallow food good for dental problems or poor feeding (take tea and toast). Also in those receiving parenteral nutrition (intravenous) for a long time where potassium supplementation is scarce. People with eating disorders like anorexia and bulimia sufferers hypokalemia among other deficiencies.
Excessive loss of potassium Gastrointestinal associated with diarrhea, severe vomiting and laxative abuse.
Urinary potassium loss given by:
excessive use of thiazide diuretics, loop or osmotic
medications such as antibiotics (penicillin G high doses, carbenicillin, ampicillin), cisplatin (chemotherapy), bronchodilators (theophylline), beta-adrenergic agents (epinephrine)
lack of magnesium: because magnesium is essential for proper maintenance of the sodium-potassium pump
metabolic alkalosis (given disorder by increasing the alkalinity or alkalinity of body fluids)
endogenous mineralocorticoid excess: as Cushing's disease, renal artery stenosis, renal tumors or adrenal gland or primary or secondary hyperaldosteronism, which increase levels of the hormone aldosterone (mineralocorticoid) and cause excessive loss of potassium in urine
exogenous mineralocorticoid excess: for steroid immunosuppression therapy for renal tubular disorders
hereditary defects in Bartter syndrome or Gitelman syndrome
DKA: there is an increased urinary potassium given by the association of an osmotic diuresis (increased urination) and excretion of ketones
Other causes: excessive sweating, alcoholism, excessive use of insulin and malnutrition
Signs and symptoms:
Muscle weakness and fatigue
Vomiting or nausea
Constipation or intestinal paralysis
Palpitations or cardiac arrhythmias
Recommended daily doses of Potassium
The following table provides adequate intake of potassium according to the Department of Nutrition IOM (Institute of Medicine: Institute of Medicine) and the USDA (United States Department of Agriculture: USDA U.S.) for both infants, children and adults.
Age Males(mg / day) Females(mg / day)
0-6 months 400 400
7-12 months 700 700
1-3 years 3000 3000
4-8 years 3800 3800
9-13 years 4500 4500
14-18 4700 4700
19 years and over 4700 4700
It is called hyperkalemia to elevated serum potassium (in plasma). Hyperkalemia occurs when potassium intake exceeds the ability of the kidney to remove the urine.
The causes of hyperkalemia caused by excessive intake of potassium, decreased potassium excretion or when the intracellular potassium passes into the extracellular space. The most common cause is due to diminished excretion by the kidney. The excessive potassium intake alone does not cause toxicity in healthy individuals. Hyperkalemia occurs normally for the individual presents various disorders at the same time.
Excessive intake: as referred to above, by itself, is unlikely to cause hyperkalemia due to renal excretion mechanisms are very efficient. In general, increased potassium intake contributes to hyperkalemia in people who have impaired renal excretion when diets low in sodium and high in potassium (potassium salts) and potassium supplements if ingested even in small quantities.
contribution of excess endogenous origin; given by the body when tissue destruction and mass acutely cells liberates a large amount of potassium into the extracellular medium. It occurs in burns, crushed limbs, hemolysis, tumor lysis syndrome and chemotherapy severe gastrointestinal bleeding.
decreased excretion: acute renal failure or chronic, Addison's disease, hyperaldosteronism, renal transplantation, diuretic, cyclosporin, lithium, etc.
trasncelular redistribution of potassium: acidosis occurs in the intense muscular exercise, type I diabetes untreated by drugs (beta-blockers, digital, fluorides, succinylcholine, cyanides) and familial periodic paralysis.