Potassium

Potassium is a chemical element with the symbol K (derived from Neo-Latin, kalium) and atomic number 19. It is a silvery-white metal that is a vital component of living cells and plays a critical role in several physiological processes in the human body. Potassium is an alkali metal and is part of group 1 of the periodic table, together with sodium, lithium, and other elements. In its pure form, it is a highly reactive metal, however, it is more commonly found in nature as part of various compounds.

Characteristics

Potassium is a soft, silvery-white metal, characteristically light enough to float on water with which it reacts instantly to release hydrogen gas and heat, sometimes causing the hydrogen to ignite.

Biological Role

Potassium is a crucial nutrient in the human body, contributing to the function of nerve cells, muscle cells, and the cardiovascular system. It helps to maintain proper electrolyte and acid-base balance in the body, and is also necessary for the function of several enzymes.

Dietary Sources and Recommended Intake

Potassium is found in many foods, with particularly high levels present in fruits such as bananas and oranges, vegetables, legumes, nuts, and dairy products. The recommended daily intake for adults is about 4,700 milligrams.

Deficiency and Overdose

A deficiency in potassium, known as hypokalemia, can cause a variety of symptoms including fatigue, muscle weakness, and irregular heartbeat. Conversely, too much potassium, known as hyperkalemia, can also have severe health effects including heart arrhythmias and can be life-threatening in severe cases.

Medical Uses

Potassium salts such as potassium chloride are commonly used in medicine to treat or prevent low levels of potassium in the blood. They are also used in lethal injections in the United States to stop the heart.

See Also

• Electrolyte imbalance
• Hypokalemia
• Hyperkalemia
• Potassium chloride

References

• 1. Emsley, John (2001). Nature's Building Blocks. Oxford: Oxford University Press. pp. 362–366.
• 2. "Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate". Institute of Medicine of the National Academies. 2004.
• 3. "Hypokalemia". Mayo Clinic. Retrieved 2014-03-12.
• 4. "Hyperkalemia". Mayo Clinic. Retrieved 2014-03-12.
• 5. "Potassium Uses, Benefits & Dosage". Drugs.com. Retrieved 2014-03-12.

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