View source for Biology:Potassium in biology

{{Short description|Use of Potassium by organisms}}
[[File:Sodium-potassium_pump.svg|thumb|200x200px|The [[Biology:Sodium–potassium pump|Sodium–potassium pump]] a critical enzyme for regulating Sodium and '''Potassium''' levels in cells]]
[[Chemistry:Potassium|Potassium]] is the main [[Biology:Intracellular|intracellular]] [[Physics:Ion|ion]] for all types of [[Biology:Cell|cell]]s, while having a major role in maintenance of [[Chemistry:Fluid balance|fluid]] and [[Physics:Electrolyte|electrolyte]] balance.<ref>
{{cite book
|last1=Pohl
|first1=Hanna R.
|last2=Wheeler
|first2=John S.
|first3=H. Edward
|last3=Murray
|editor=Astrid Sigel, Helmut Sigel and Roland K. O. Sigel
|title=Interrelations between Essential Metal Ions and Human Diseases
|series=Metal Ions in Life Sciences
|volume=13
|year=2013
|publisher=Springer
|pages=29–47
|chapter=Chapter 2. Sodium and Potassium in Health and Disease
|doi=10.1007/978-94-007-7500-8_2
|pmid=24470088
}}</ref><ref>*{{cite book 
|last1=Clausen |first1=Michael Jakob Voldsgaard |last2=Poulsen |first2=Hanne  
|chapter=Sodium/Potassium Homeostasis in the Cell |editor1-first=Lucia|editor1-last=Banci |series=Metal Ions in Life Sciences |volume=12 
|title=Metallomics and the Cell |year=2013 |pages=41–67 |publisher=Springer |isbn=978-94-007-5560-4|doi=10.1007/978-94-007-5561-1_3|pmid=23595670 }} electronic-book {{ISBN|978-94-007-5561-1}} {{issn|1559-0836}} electronic-{{issn|1868-0402}}
</ref> Potassium is necessary for the function of all living cells, and is thus present in all plant and animal tissues. It is found in especially high concentrations within plant cells, and in a mixed diet, it is most highly concentrated in fruits. The high concentration of potassium in plants, associated with comparatively very low amounts of sodium there, historically resulted in potassium first being isolated from the ashes of plants ([[Chemistry:Potash|potash]]), which in turn gave the element its modern name. The high concentration of potassium in plants means that heavy crop production rapidly depletes soils of potassium, and agricultural fertilizers consume 93% of the potassium chemical production of the modern world economy.

The functions of potassium and sodium in living organisms are quite different. Animals, in particular, employ sodium and potassium differentially to generate electrical potentials in animal cells, especially in [[Biology:Nervous tissue|nervous tissue]]. Potassium depletion in animals, including humans, results in various neurological dysfunctions. Characteristic concentrations of potassium in model organisms are: 30–300mM in ''E. coli'', 300mM in budding yeast, 100mM in mammalian cell and 4mM in blood plasma.<ref>{{cite web|url= http://book.bionumbers.org/what-are-the-concentrations-of-different-ions-in-cells/|title= Cell Biology by the Numbers: What are the concentrations of different ions in cells?|website= book.bionumbers.org|first1= Ron|last1= Milo|first2= Rob|last2= Philips|access-date= 23 March 2017|url-status= live|archive-url= https://web.archive.org/web/20170420041741/http://book.bionumbers.org/what-are-the-concentrations-of-different-ions-in-cells/|archive-date= 20 April 2017}}</ref>

== Function in plants ==
{{See also|Potassium deficiency (plants)}}The main role of potassium in plants is to provide the ionic environment for metabolic processes in the [[Biology:Cytosol|cytosol]], and as such functions as a regulator of various processes including growth regulation.<ref>{{cite journal |last1=Leigh |first1=R. A. |last2=Wyn Jones |first2=R. G. |year=1984 |title=A Hypothesis Relating Critical Potassium Concentrations for Growth to the Distribution and Functions of This Ion in the Plant Cell |url=https://repository.rothamsted.ac.uk/download/ad74fdb75c484f38a9cff7e181f511086794c1803546d3c581ace20378c645e9/914530/8998.pdf |journal=New Phytologist |volume=97 |issue=1 |pages=1–13 |doi=10.1111/j.1469-8137.1984.tb04103.x |jstor=2434189 |doi-access=free}}</ref> Plants require potassium [[Physics:Ion|ion]]s (K<sup>+</sup>) for protein synthesis and for the opening and closing of [[Biology:Stoma|stoma]]ta, which is regulated by [[Physics:Proton pump|proton pump]]s to make surrounding guard cells either [[Biology:Turgor pressure|turgid]] or flaccid.  A deficiency of potassium ions can impair a plant's ability to maintain these processes. Potassium also functions in other physiological processes such as [[Earth:Photosynthesis|photosynthesis]], protein synthesis, activation of some [[Biology:Enzymes|enzymes]], phloem solute transport of photoassimilates into source organs, and maintenance of cation:anion balance in the cytosol and [[Biology:Vacuole|vacuole]].<ref name="b1">Hopkins, W.G. and Huner, N.P.A. ''Introduction to Plant Physiology'' 4th edition</ref>

==Function in animals==
Potassium is the major cation (K<sup>+</sup>, a positive ion) inside [[Biology:Cell|animal cells]], while [[Chemistry:Sodium|sodium]] (Na<sup>+</sup>) is the major cation outside animal cells. The difference between the concentrations of these charged particles causes a difference in [[Physics:Electric potential|electric potential]] between the inside and outside of cells, known as the [[Biology:Membrane potential|membrane potential]].  The balance between potassium and sodium is maintained by [[Biology:Ion transporter|ion transporter]]s in the [[Biology:Cell membrane|cell membrane]]. All potassium ion channels are tetramers with several conserved secondary structural elements. A number of potassium channel structures have been [[Physics:X-ray crystallography|solved]] including [[Biology:Voltage-gated potassium channel|voltage gated]],<ref>{{cite journal|pmid=23095758 | doi=10.1074/jbc.M112.415091 | volume=287 | issue=51 | title=Crystal structure of a voltage-gateds K+ channel pore module in a closed state in lipid membranes. | date=Dec 2012 | journal=J Biol Chem | pages=43063–70 | pmc=3522301 | vauthors=Santoss JS, Asmar-Rovira GA, Han GW, Liu W, Syeda R, Cherezov V, Baker KA, Stevens RC, Montal M| doi-access=free }}</ref><ref>{{cite journal|pmid=16002581 | doi=10.1126/science.1116269 | volume=309 | issue=5736 | title=Crystal structure of a mammalian voltage-dependent Shaker family K+ channel | date=August 2005 | journal=Science | pages=897–903 |vauthors=Long SB, Campbell EB, Mackinnon R | bibcode=2005Sci...309..897L | s2cid=6072007 | doi-access=free }}</ref><ref>{{cite journal|pmid=12721618 | doi=10.1038/nature01580 | volume=423 | issue=6935 | title=X-ray structure of a voltage-dependent K+ channel | date=May 2003 | journal=Nature | pages=33–41 |vauthors=Jiang Y, Lee A, Chen J | bibcode=2003Natur.423...33J | s2cid=4347957 |display-authors=0}}</ref> [[Biology:Calcium-activated potassium channel|ligand gated]],<ref>{{cite journal|pmid=12037559 | doi=10.1038/417515a | volume=417 | issue=6888 | title=Crystal structure and mechanism of a calcium-gated potassium channel | date=May 2002 | journal=Nature | pages=515–22 |vauthors=Jiang Y, Lee A, Chen J, Cadene M, Chait BT, MacKinnon R | bibcode=2002Natur.417..515J | s2cid=205029269 }}</ref><ref>{{cite journal|pmid=20508092 | doi=10.1126/science.1190414 | pmc=3022345 | volume=329 | issue=5988 | title=Structure of the human BK channel Ca2+-activation apparatus at 3.0 A resolution | date=July 2010 | journal=Science | pages=182–6 |vauthors=Yuan P, Leonetti MD, Pico AR, Hsiung Y, MacKinnon R | bibcode=2010Sci...329..182Y }}</ref><ref>{{cite journal|pmid=20574420 | doi=10.1038/nature09252 | pmc=2910425 | volume=466 | issue=7304 | title=Structure of the gating ring from the human large-conductance Ca(2+)-gated K(+) channel | date=July 2010 | journal=Nature | pages=393–7 |vauthors=Wu Y, Yang Y, Ye S, Jiang Y }}</ref><ref>{{cite journal|pmid=23129643 | doi=10.1073/pnas.1215078109 | volume=109 | issue=47 | title=Functional and structural analysis of the human SLO3 pH- and voltage-gated K+ channel. | date=Nov 2012 | journal=Proc Natl Acad Sci U S A | pages=19274–9 | pmc=3511096 | vauthors=Leonetti MD, Yuan P, Hsiung Y, Mackinnon R| bibcode=2012PNAS..10919274L | doi-access=free }}</ref><ref>{{cite journal|pmid=23240087 | doi=10.7554/eLife.00184 | pmc=3510474 | volume=1 | title=Distinct gating mechanisms revealed by the structures of a multi-ligand gated K(+) channel. | year=2012 | journal=eLife | pages=e00184 | vauthors=Kong C, Zeng W, Ye S, Chen L, Sauer DB, Lam Y, Derebe MG, Jiang Y | doi-access=free }}</ref> tandem-pore,<ref>{{cite journal|pmid=22282805 | doi=10.1126/science.1213808 | pmc=3329120 | volume=335 | issue=6067 | title=Crystal structure of the human K2P TRAAK, a lipid- and mechano-sensitive K+ ion channel | date=January 2012 | journal=Science | pages=4s36–41 |vauthors=Brohawn SG, del Mármol J, MacKinnon R | bibcode=2012Sci...335..436B }}</ref><ref>{{cite journal|pmid=22282804 | doi=10.1126/science.1213274 | volume=335 | issue=6067 | title=Crystal structure of the human two-pore domain potassium channel K2P1 | date=January 2012 | journal=Science | pages=432–6 |vauthors=Miller AN, Long SB | bibcode=2012Sci...335..432M | s2cid=206537279 }}</ref><ref>{{cite journal|pmid=25766236 | doi=10.1126/science.1261512 | volume=347 | issue=6227 | title=K2P channel gating mechanisms revealed by structures of TREK-2 and a complex with Prozac. | date=Mar 2015 | journal=Science | pages=1256–9 | vauthors=Dong YY, Pike AC, Mackenzie A, McClenaghan C, Aryal P, Dong L, Quigley A, Grieben M, Goubin S, Mukhopadhyay S, Ruda GF, Clausen MV, Cao L, Brennan PE, Burgess-Brown NA, Sansom MS, Tucker SJ, Carpenter EP| pmc=6034649 | bibcode=2015Sci...347.1256D }}</ref> and inwardly rectifying channels,<ref>{{cite journal|pmid=20564790 | volume=141 | issue=6 | title=Domain reorientation and rotation of an intracellular assembly regulate conduction in Kir potassium channels. | date=Jun 2010 | journal=Cell | pages=1018–29 | doi=10.1016/j.cell.2010.05.003 | vauthors=Clarke OB, Caputo AT, Hill AP, Vandenberg JI, Smith BJ, Gulbis JM| s2cid=14484301 | doi-access=free }}</ref><ref>{{cite journal|pmid=12738871 | doi=10.1126/science.1085028 | volume=300 | issue=5627 | title=Crysstal structure of the potassium channel KirBac1.1 in the closed state. | date=Jun 2003 | journal=Science | pages=1922–6 | vauthors=Kuo A, Gulbis JM, Antcliff JF, Rahman T, Lowe ED, Zimmer J, Cuthbertson J, Ashcroft FM, Ezaki T, Doyle DA| bibcode=2003Sci...300.1922K | s2cid=2703162 | doi-access=free }}</ref><ref>{{cite journal|pmid=21962516 | doi=10.1016/j.cell.2011.07.046 | volume=147 | issue=1 | title=Crystal structures of the mammalian GIRK2 K+ channel and gating regulation by G proteins, PIP2, and sodium. | date=Sep 2011 | journal=Cell | pages=199–208 | pmc=3243363 | vauthors=Whorton MR, MacKinnon R}}</ref><ref>{{cite journal|pmid=12507423 | volume=111 | issue=7 | title=Structural basis of inward rectification: cytoplasmic pore of the G protein-gated inward rectifier GIRK1 at 1.8 A resolution. | date=Dec 2002 | journal=Cell | pages=957–65 | doi = 10.1016/S0092-8674(02)01227-8 | vauthors=Nishida M, MacKinnon R| s2cid=15788511 | doi-access=free }}</ref><ref>{{cite journal|pmid=20019282 | doi=10.1126/science.1180310 | volume=326 | issue=5960 | title=Crystal structure of the eukaryotic strong inward-rectifier K+ channel Kir2.2 at 3.1 A resolution. | date=Dec 2009 | journal=Science | pages=1668–74 | pmc=2819303 | vauthors=Tao X, Avalos JL, Chen J, MacKinnon R| bibcode=2009Sci...326.1668T }}</ref> from [[Biology:Prokaryote|prokaryote]]s and [[Biology:Eukaryote|eukaryote]]s. The cell membrane potential created by potassium and sodium  ions allows the cell to generate an [[Biology:Action potential|action potential]]&mdash;a "spike" of electrical discharge. The ability of cells to produce electrical discharge is critical for body functions such as [[Biology:Neurotransmission|neurotransmission]], muscle contraction, and heart function.<ref name="pmid16253415">{{cite journal |author1=Mikko Hellgren |author2=Lars Sandberg |author3=Olle Edholm |title=A comparison between two prokaryotic potassium channels (K<sub>ir</sub>Bac1.1 and KcsA) in a molecular dynamics (MD) simulation study |journal=Biophys. Chem. |volume=120 |issue=1 |pages=1–9 |year=2006 |pmid=16253415 |doi=10.1016/j.bpc.2005.10.002}}</ref>

==Dietary recommendations==
The U.S. National Academy of Medicine (NAM), on behalf of both the U.S. and Canada, sets [[Chemistry:Dietary Reference Intake|Dietary Reference Intake]]s, including Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs), or Adequate Intakes (AIs) for when there is not sufficient information to set EARs and RDAs.

For both males and females under 9 years of age, the AIs for potassium are: 400{{nbsp}}mg of potassium for 0 to 6-month-old infants, 860{{nbsp}}mg of potassium for 7 to 12-month-old infants, 2,000{{nbsp}}mg of potassium for 1 to 3-year-old children, and 2,300{{nbsp}}mg of potassium for 4 to 8-year-old children.

For males 9 years of age and older, the AIs for potassium are: 2,500{{nbsp}}mg of potassium for 9 to 13-year-old males, 3,000{{nbsp}}mg of potassium for 14 to 18-year-old males, and 3,400{{nbsp}}mg for males that are 19 years of age and older.

For females 9 years of age and older, the AIs for potassium are: 2,300{{nbsp}}mg of potassium for 9 to 18-year-old females, and 2,600{{nbsp}}mg of potassium for females that are 19 years of age and older.

For pregnant and lactating females, the AIs for potassium are: 2,600{{nbsp}}mg of potassium for 14 to 18-year-old pregnant females, 2,900{{nbsp}}mg for pregnant females that are 19 years of age and older; furthermore, 2,500{{nbsp}}mg of potassium for 14 to 18-year-old lactating females, and 2,800{{nbsp}}mg for lactating females that are 19 years of age and older. As for safety, the NAM also sets tolerable upper intake levels (ULs) for vitamins and minerals, but for potassium the evidence was insufficient, so no UL was established.<ref>{{cite book |author=National Academies of Sciences, Engineering and Medicine |editor3-first=Maria |editor3-last=Oria |editor2-first=Meghan |editor2-last=Harrison |editor1-first=Virginia A |editor1-last=Stallings |date=2019 |title=Dietary Reference Intakes for Sodium and Potassium |location=Washington, DC |publisher=The National Academies Press |chapter=Potassium: Dietary Reference Intakes for Adequacy |chapter-url=https://www.nap.edu/read/25353/chapter/8 |isbn= 978-0-309-48834-1|doi=10.17226/25353 |doi-access=free |pmid=30844154}}</ref><ref>{{cite book |url=http://www.nationalacademies.org/hmd/Reports/2019/dietary-reference-intakes-sodium-potassium.aspx |title=Dietary Reference Intakes for Sodium and Potassium – Publication |date=March 5, 2019 |website=Health and Medicine Division |publisher=National Academies of Sciences, Engineering and Medicine |doi=10.17226/25353 |pmid=30844154 |isbn=978-0-309-48834-1 |s2cid=104464967 |access-date=May 13, 2019 |editor1-last=Stallings |editor1-first=Virginia A |editor2-first=Meghan |editor2-last=Harrison |editor3-first=Maria |editor3-last=Oria }}</ref>

In 2019, the [[Organization:National Academies of Sciences, Engineering, and Medicine|National Academies of Sciences, Engineering, and Medicine]] revised the Adequate Intake for potassium to 2,600&nbsp;mg/day for females 19 years of age and older who are not pregnant or lactating, and 3,400&nbsp;mg/day for males 19 years of age and older.<ref>{{cite press release |title=Sodium and Potassium Dietary Reference Intake Values Updated in New Report; Introduces New Category for Sodium Based on Chronic Disease Risk Reduction |url=https://www.nationalacademies.org/news/2019/03/sodium-and-potassium-dietary-reference-intake-values-updated-in-new-report |publisher=[[Organization:National Academies of Sciences, Engineering, and Medicine|National Academies of Sciences, Engineering, and Medicine]] |date=5 March 2019 |access-date=29 January 2022}}</ref><ref>{{cite book | title=Dietary Reference Intakes for Sodium and Potassium | date=March 2019 | url=https://www.ncbi.nlm.nih.gov/books/NBK538102/ | access-date=13 November 2022 | id=Bookshelf ID: NBK538102 | vauthors=((National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium)) | veditors=Oria M, Harrison M, Stallings VA | doi=10.17226/25353 | isbn=978-0-309-48834-1 |publisher=National Academies Press | pmid=30844154 | s2cid=104464967 }}</ref>

The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL defined the same as in United States. For people ages 15 and older the AI is set at 3,500&nbsp;mg/day. AIs for pregnancy is 3,500&nbsp;mg/day, for lactation 4,000&nbsp;mg/day. For children ages 1–14 years the AIs increase with age from 800 to 2,700&nbsp;mg/day. These AIs are lower than the U.S. RDAs.<ref>{{cite web| title = Overview on Dietary Reference Values for the EU population as derived by the EFSA Panel on Dietetic Products, Nutrition and Allergies| year = 2017| url = https://www.efsa.europa.eu/sites/default/files/assets/DRV_Summary_tables_jan_17.pdf| url-status = live| archive-url = https://web.archive.org/web/20170828082247/https://www.efsa.europa.eu/sites/default/files/assets/DRV_Summary_tables_jan_17.pdf| archive-date = 2017-08-28}}</ref> The EFSA reviewed the same safety question and decided that there was insufficient data to establish a UL for potassium.<ref>{{citation| title = Tolerable Upper Intake Levels For Vitamins And Minerals| publisher = European Food Safety Authority| year = 2006| url = http://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf| url-status = live| archive-url = https://web.archive.org/web/20160316225123/http://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf| archive-date = 2016-03-16}}</ref>

===Labeling===
For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For potassium labeling purposes 100% of the Daily Value was 3500&nbsp;mg, but as of May 2016, it has been revised to 4700&nbsp;mg.<ref name="FedReg">{{cite web |url=https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf |title=Federal Register May 27, 2016 Food Labeling: Revision of the Nutrition and Supplement Facts Labels. FR page 33982. |url-status=live |archive-url=https://web.archive.org/web/20160808164651/https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf |archive-date=August 8, 2016 }}</ref><ref>{{cite web | title=Daily Value Reference of the Dietary Supplement Label Database (DSLD) | website=Dietary Supplement Label Database (DSLD) | url=https://www.dsld.nlm.nih.gov/dsld/dailyvalue.jsp | access-date=16 May 2020}}</ref> A table of the old and new adult Daily Values is provided at [[Chemistry:Reference Daily Intake|Reference Daily Intake]].

==Supplements==
20 mEq (781&nbsp;mg) potassium from [[Chemistry:Potassium gluconate|potassium gluconate]] (4680&nbsp;mg), or [[Chemistry:Potassium citrate|potassium citrate]] (2040&nbsp;mg), mixed a half-cup (1.12 dL) water, taken two to four times a day, may be used on daily basis.<ref>{{cite web |title=Potassium Supplement (Oral Route, Parenteral Route) Proper Use - Mayo Clinic |url=https://www.mayoclinic.org/drugs-supplements/potassium-supplement-oral-route-parenteral-route/proper-use/drg-20070753 |website=www.mayoclinic.org}}</ref><ref>{{cite web |title=NCATS Inxight Drugs — POTASSIUM GLUCONATE |url=https://drugs.ncats.io/drug/12H3K5QKN9 |website=drugs.ncats.io |language=en}}</ref>

===Labeling===
Because of the risk of small-bowel lesions, the US FDA requires some potassium [[Chemistry:Salt|salt]]s (for example [[Chemistry:Potassium chloride|potassium chloride]]) containing more than 99&nbsp;mg (about 1.3 mEq) to be labeled with a warning.<ref>{{cite web |title=Office of Dietary Supplements - Potassium |url=https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/ |website=ods.od.nih.gov |language=en}}</ref>

==Food sources==
Eating a variety of foods that contain potassium is the best way to get an adequate amount. 
Foods with high sources of potassium include [[Biology:Kiwifruit|kiwifruit]], orange juice, [[Biology:Potato|potato]]es, [[Biology:Coconut|coconut]], [[Biology:Avocado|avocado]]s, [[Biology:Apricot|apricot]]s, [[Biology:Parsnip|parsnip]]s and [[Biology:Turnip|turnip]]s, although many other [[Biology:Fruit|fruit]]s, vegetables, legumes, and meats contain potassium.

Common foods very high in potassium:<ref name="healthaliciousness.com">{{cite web|url=http://www.healthaliciousness.com/articles/food-sources-of-potassium.php#potassium-density-by-gram|title=Top 10 Foods Highest in Potassium + One Page Printable|website=myfooddata|url-status=live|archive-url=https://web.archive.org/web/20140911023200/http://www.healthaliciousness.com/articles/food-sources-of-potassium.php#potassium-density-by-gram|archive-date=2014-09-11}}</ref>
* beans (white beans and others)
* dark leafy greens (spinach, Swiss chard, and others)
* baked potatoes
* dried fruit (apricots, peaches, prunes, raisins; figs and dates)
* baked squash
* yogurt
* fish (salmon)
* avocado
* nuts (pistachios, almonds, walnuts, etc.) 
* seeds (squash, pumpkin, sunflower)

Foods containing the highest concentration:<ref name="healthaliciousness.com"/>
* dried herbs
* sun dried tomatoes
* cocoa solids<ref>{{cite web |title=FoodData Central |url=https://fdc.nal.usda.gov/fdc-app.html#/food-details/169593/nutrients |website=fdc.nal.usda.gov}}</ref> 
* whey powder
* paprika
* yeast extract
* rice bran
* molasses
* dry roasted soybeans

== Deficiency ==

=== High blood pressure/Hypertension ===
Diets low in potassium increase risk of hypertension, stroke and cardiovascular disease.<ref>{{cite journal |vauthors=Aburto NJ, Hanson S, Gutierrez H, Hooper L, Elliott P, Cappuccio FP |title=Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses |journal=BMJ |volume=346 |pages=f1378 |year=2013 |pmid=23558164 |pmc=4816263 |doi= 10.1136/bmj.f1378}}</ref><ref>{{cite journal |vauthors=D'Elia L, Barba G, Cappuccio FP, Strazzullo P |title=Potassium intake, stroke, and cardiovascular disease a meta-analysis of prospective studies |journal=J. Am. Coll. Cardiol. |volume=57 |issue=10 |pages=1210–9 |year=2011 |pmid=21371638 |doi=10.1016/j.jacc.2010.09.070 |doi-access=free }}</ref>

=== Hypokalemia ===
A severe shortage of potassium in body fluids may cause a potentially fatal condition known as [[Medicine:Hypokalemia|hypokalemia]].  Hypokalemia typically results from loss of potassium through  [[Medicine:Diarrhea|diarrhea]], diuresis, or vomiting. Symptoms are related to alterations in  membrane potential and cellular metabolism.  Symptoms include muscle weakness and cramps, paralytic [[Medicine:Ileus|ileus]], ECG abnormalities, intestinal paralysis, decreased reflex response and (in severe cases) respiratory paralysis, alkalosis and [[Medicine:Heart arrhythmia|arrhythmia]].

In rare cases, habitual consumption of large amounts of black licorice has resulted in hypokalemia. Licorice contains a compound ([[Chemistry:Glycyrrhizin|Glycyrrhizin]]) that increases urinary excretion of potassium.<ref>{{cite journal |vauthors=Mumoli N, Cei M |title=Licorice-induced hypokalemia |journal=Int. J. Cardiol. |volume=124 |issue=3 |pages=e42–4 |year=2008 |pmid=17320224 |doi=10.1016/j.ijcard.2006.11.190 }}</ref>

=== Insufficient intake ===
Adult women in the United States consume on average half the AI, for men two-thirds. For all adults, fewer than 5% exceed the AI.<ref>[https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/1314/Table_1_NIN_GEN_13.pdf What We Eat In America, NHANES 2013-2014] {{webarchive|url=https://web.archive.org/web/20170224042515/https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/1314/Table_1_NIN_GEN_13.pdf |date=2017-02-24 }}.</ref> Similarly, in the [[Social:European Union|European Union]], insufficient potassium intake is widespread.<ref>{{cite web |url=http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ProduktNr=223977&Ausgabe=230671&ArtikelNr=83312&filename=83312.pdf |title=Archived copy |access-date=2007-01-30 |url-status=live |archive-url=https://web.archive.org/web/20110713135630/http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ProduktNr=223977&Ausgabe=230671&ArtikelNr=83312&filename=83312.pdf |archive-date=2011-07-13 }} Energy and Nutrient Intake in the European Union</ref>

== Side effects and toxicity ==

Gastrointestinal  symptoms are the most common side effects of potassium supplements, including nausea, vomiting, abdominal discomfort, and diarrhea.  Taking potassium with meals or taking a  microencapsulated form of potassium may reduce gastrointestinal side effects.

[[Medicine:Hyperkalemia|Hyperkalemia]] is the most serious adverse reaction to potassium.  Hyperkalemia occurs when potassium builds up faster than the kidneys can remove it. It is most common in individuals with renal failure.  Symptoms of hyperkalemia may include tingling of the hands and feet, muscular weakness, and temporary paralysis. The most serious complication of hyperkalemia is the development of an abnormal heart rhythm ([[Medicine:Heart arrhythmia|arrhythmia]]), which can lead to cardiac arrest.

Although hyperkalemia is rare in healthy individuals, oral doses greater than 18&nbsp;grams taken at one time in individuals not accustomed to high intakes can lead to hyperkalemia.

== See also ==

* [[:Category:Biology and pharmacology of chemical elements|Biology and pharmacology of chemical elements]]
* {{annotated link|Biology:Action potential}}
* {{annotated link|Biology:Calcium in biology}}
* {{annotated link|Physics:Electrolyte}}
* {{annotated link|Biology:Iodine in biology}}
* {{annotated link|Biology:Magnesium in biology}}
* {{annotated link|Biology:Membrane potential}}
* {{annotated link|Biology:Selenium in biology}}
* {{annotated link|Biology:Sodium in biology}}

== References ==
{{Reflist}}

== Further reading ==
* {{cite web | title=Potassium Health Professional Fact Sheet | website=NIH Office of Dietary Supplements | date=3 April 2020 | url=https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/ }}

== External links ==
* {{cite web | url = https://druginfo.nlm.nih.gov/drugportal/name/potassium | publisher = U.S. National Library of Medicine | work = Drug Information Portal | title = Potassium }}
* [http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/ion_pump/ionpump.html Brooks/Cole publishers &ndash; Sodium Potassium pump]
*[https://lpi.oregonstate.edu/mic/minerals/potassium Oregon State University &ndash; Micronutrient Information Center]
* Potassium at [https://labtestsonline.org/tests/potassium Lab Tests Online]
* [https://www.webarchive.org.uk/wayback/archive/20130416111342/http://www.acb.org.uk/docs/NHLM/Potassium.pdf Potassium: analyte monograph] - the Association for Clinical Biochemistry and Laboratory Medicine.

{{Clinical biochemistry blood tests}}


{{DEFAULTSORT:Potassium In Biology}}
[[Category:Biological systems]]
[[Category:Biology and pharmacology of chemical elements]]
[[Category:Dietary minerals]]
[[Category:Potassium|Biology]]

{{Sourceattribution|Potassium in biology}}