Potassium Deficiency - Symptoms, Causes, Therapy
Potassium is required as an essential mineral for numerous bodily functions. It is present in all cells and contributes to their proper functioning. Among other things, potassium is involved in the regulation of impulse transmission and fluid balance. Additionally, potassium is needed for protein and carbohydrate metabolism. When the body lacks potassium, it is referred to as hypokalemia in medical terms.
Potassium deficiency is relatively rare but can lead to serious health consequences and even become life-threatening.
The risk group includes:
- People suffering from poor nutrient absorption (e.g., due to Crohn's disease)
- People taking diuretics such as thiazide diuretics (which eliminate water from the body), laxatives, and antibiotics 1 2
- Individuals with eating disorders
- Elderly individuals
- Alcoholics 3
- Dialysis patients 4
- Patients with diabetic ketoacidosis 5
- Endurance athletes
- Individuals engaged in physically demanding activities
The causes of potassium deficiency in the body can be diverse. One cause can be an inadequate supply of potassium to the body. Consuming predominantly processed and heavily processed foods can lead to malnutrition with low potassium levels 6. However, potassium deficiency due to a low-potassium diet is relatively rare.
Diarrhea can also lead to a deficiency. It contains high levels of potassium (30-60 mmol/l) and bicarbonate 7. The use of various medications, especially diuretics and laxatives, can also trigger potassium deficiency 8. Potassium is then lost in larger quantities through stool and urine. Antibiotics such as Amphotericin B, Carbenicillin, Foscarnet, Gentamicin, Nafcillin, Sodium Penicillin, and Penicillin also lead to potassium loss through the kidneys. Patients with diarrhea often suffer from hyperchloremic metabolic acidosis 9. Acidosis is a disturbance of the acid-base balance. The body tries to compensate for the loss of bicarbonate by using chloride.
An imbalance in the acid-base equilibrium can also be a cause of potassium deficiency. In the case of alkalosis (increase in pH value), potassium concentrations shift into the cells. As a result, the hormone aldosterone is released in greater amounts, leading to increased potassium excretion through the kidneys until potassium levels return to normal. Additionally, potassium concentrations outside the cells decrease. Furthermore, catecholamines, insulin, and certain medications (such as beta-2 sympathomimetics) also stimulate the shift of potassium into the cells, which can result in depletion of potassium levels 10 11 12.
Depending on the frequency, vomiting can also lead to potassium deficiency. Vomit contains high levels of acid and low levels of potassium (5–10 mmol/l) 13. The loss of acid leads to alkalosis, causing potassium to shift into the cells.
The cause can be an absorption disorder of potassium from the diet or a dysfunction of the kidneys or adrenal glands (such as renal tubular acidosis and renal artery stenosis) 14. Possible diseases and genetic defects that lead to potassium loss through the kidneys include: hyperaldosteronism (Conn syndrome), Bartter syndrome, Cushing syndrome, Fanconi syndrome, and Liddle syndrome 15 16 17 18. Another possible cause is a gastrointestinal tract disorder leading to potassium malabsorption 19.
A hormonal disorder that leads to increased production of mineralocorticoids and glucocorticoids can also cause potassium loss through the kidneys 20.
Since potassium is also lost through sweat, in rare cases, prolonged physical activity or occupations that cause excessive sweating can lead to potassium deficiency.
Potassium deficiency can be triggered and worsened by a magnesium deficiency 21 22 23. A deficiency of magnesium leads to a decrease in cellular potassium concentrations and increased excretion of potassium through the kidneys, making treatment of potassium deficiency only meaningful with simultaneous administration of magnesium and correction of magnesium deficiency 24 25 26 27. In this context, magnesium levels should also be checked 28. Simultaneous magnesium and potassium deficiency can be caused by diarrhea and diuretics 29. It is advisable to maintain a magnesium-rich diet.
An excessive consumption of licorice can also lower the potassium level in the body and initiate hypokalemia 30 31. Licorice contains glycyrrhizin, a substance that acts similarly to aldosterone and leads to increased potassium excretion 32. Additionally, a high consumption of cola and coffee can also lead to potassium deficiency 33 34 35 36 37.
Other possible causes can include certain diets, alcohol consumption, and diabetic ketoacidosis.
When experiencing mild potassium deficiency with a slight decrease in potassium levels, the body often does not show any symptoms 38 39. When potassium levels drop significantly, the first symptoms may appear. The symptoms primarily depend on changes in concentrations in the intra- and extracellular areas, as well as alterations in cellular metabolism. The functions of nerves and muscles are primarily affected.
- Cardiovascular problems
- Higher blood pressure
- Sleep disorders
- Muscle weakness
- Muscle tingling, muscle burning, numbness (paresthesia)
- Muscle pain (myalgia)
- Lack of appetite
- Digestive disorders such as constipation and bloating
- Lack of drive/apathy
- Fluid retention in tissues (edema)
- Respiratory difficulties
There is a concentration gradient between the cells (intracellular space) and the area outside the cell (extracellular space), which is maintained by the sodium-potassium pump. As a result, only 2% of the body's potassium is located outside the cells, while 98% is found within the cells 42. Even slight shifts in potassium concentrations can have negative effects on heart rhythm (dysrhythmias, atrial fibrillation, and ventricular fibrillation) and the overall functions of potassium, which can become life-threatening 43 44 45. Heart failure and respiratory arrest can result from severe potassium deficiency 46 47 48.
In addition, a severe potassium deficiency can lead to paralysis such as muscle paralysis, intestinal paralysis associated with bloating and constipation. 49 50. Serious muscle damage such as rhabdomyolysis (rapid breakdown of muscle fibers), which manifests as increased sensitivity and swelling of the muscles, can be a consequence. 51 52. Cardiovascular manifestations such as high blood pressure can also be a consequence of excessive sodium intake and inadequate potassium intake. 53.
Low potassium intake has been associated with stiffer arteries in younger healthy individuals. 54. Arteries are blood vessels that carry blood away from the heart. Oxygen and nutrients are transported through these vessels. The stiffer the blood vessels, the higher the blood pressure needs to be to pump blood through the arteries. This increases the workload on the heart. Stiff arteries primarily increase systolic blood pressure and can be a cause of heart attack and stroke, among other conditions. Patients with pre-existing conditions such as atherosclerosis, hypertension, and coronary heart disease may be particularly affected by the consequences of potassium deficiency. 55.
Other potential consequences can include insulin resistance and impaired insulin release (leading to the development of diabetes), bladder dysfunction, kidney damage, formation of kidney stones, and polyuria (excessive urine production) 56.
Detecting Potassium Deficiency
Abnormalities in measuring heart activities using ECG (including decrease in T-wave amplitude, ST-segment depressions, and prolongation of the Q-T interval) may indicate potassium deficiency 57 58 59.
Potassium deficiency can be detected by measuring the potassium levels in urine and blood plasma. If more than >15 mmol of potassium is excreted in 24 hours, there is excessive loss through the kidneys 60. If the value is below 15 mmol/24 hours, potassium loss through the gastrointestinal tract (often due to diarrhea and vomiting) is the most likely cause. ECG can confirm the changes and symptoms that occur due to potassium deficiency.
|Condition||Serum Potassium Concentration|
(with few to no symptoms)
|moderate hypokalemia||2.5-3.0 mmol/l|
|severe hypokalemia||<2.5 mmol/l|
In addition to measuring potassium levels, the serum levels of bicarbonate, chloride, phosphate, and magnesium can also be helpful in the diagnosis. 64.
When determining potassium levels, changes in the acid-base balance should also be considered in the serum pH values. If the pH values decrease, potassium levels in the serum increase because potassium flows from the intracellular to extracellular space. If the pH value in the serum increases, potassium shifts into the cells. With a pH increase of 0.1 units, the potassium level decreases by 0.3 mmol/L. 65. Restoring optimal acid-base balance may resolve potassium deficiency.
The appropriate therapy depends on the underlying cause.
If there is no illness present, a potassium deficiency can be easily corrected through a potassium-rich diet and dietary supplements. It is advisable to supplement one's diet with dietary supplements in consultation with a doctor. Administered dosages typically range from 40-100 mmol potassium chloride spread throughout the day 68. If there is also a phosphate deficiency, potassium phosphate will be prescribed - potassium hydrogen carbonate in patients with acidosis 69.
A serum decrease in potassium by 0.3 mmol/l suggests a potassium deficiency of 100 mmol in the body 70. A patient with a potassium level of 2.6 mmol would need to intake at least 300 mmol of potassium to correct the deficiency.
For serum levels below 3.0 mmol, potassium chloride can be administered at a dose of 40 mmol every 3 to 4 hours, three times a day 71. In the case of severe potassium deficiency (<2.5 mmol/L), potassium can be administered intravenously in the form of potassium chloride. Intravenous therapy is appropriate for patients with intestinal dysfunction, neurological symptoms, cardiac arrhythmias, digitalis toxicity, and cardiac ischemia 72. It should be noted that potassium should not be administered too rapidly 73. The infusion rate should not exceed 20 mmol per hour, and potassium levels should be checked every two to four hours 74 75. Meanwhile, with intravenous administration, the heart activities should be monitored via EKG.
If there is also a magnesium deficiency, treatment with potassium magnesium L-aspartate is recommended 76.
In patients with renal failure, an excessive supply of potassium can lead to potassium excess, which can also result in negative effects.
The serum levels should be rechecked after treatment.
To prevent potassium deficiency in healthy individuals, it is advisable to consume potassium-rich foods such as potassium-rich fruits and potassium-rich vegetables, as well as whole grains. When cooking potassium-rich foods, it is important to note that potassium is water-soluble. Therefore, a significant amount of potassium is found in the cooking water, which can be used as a base for soups.
Additionally, it is important to drink plenty of fluids throughout the day to maintain the balance of potassium and electrolytes.