Editing Potassium (section)

==Biological role==
{{Main|Potassium in biology}}
Potassium is the eighth or ninth most common element by mass (0.2%) in the human body, so that a 60{{nbsp}}kg adult contains a total of about 120{{nbsp}}g of potassium.<ref>{{cite journal|doi = 10.1016/0883-2889(92)90208-V|title = A simple calibration of a whole-body counter for the measurement of total body potassium in humans|year = 1992|last1 = Abdel-Wahab|first1 = M.|last2 = Youssef|first2 = S.|last3 = Aly|first3 = A.|last4 = el-Fiki|first4 = S.|last5 = el-Enany|first5 = N.|last6 = Abbas|first6 = M.|journal = International Journal of Radiation Applications and Instrumentation A|volume = 43|issue = 10|pages = 1285–9|pmid=1330980}}</ref> The body has about as much potassium as sulfur and chlorine, and only calcium and phosphorus are more abundant (with the exception of the ubiquitous [[CHON]] elements).<ref>{{cite book|author=Chang, Raymond |title=Chemistry|url=https://books.google.com/books?id=huSDQAAACAAJ|date= 2007|publisher=McGraw-Hill Higher Education|isbn=978-0-07-110595-8|page=52}}</ref> Potassium ions are present in a wide variety of proteins and enzymes.<ref>{{cite book|first1= Milan |last1= Vašák|first2= Joachim |last2= Schnabl|publisher= Springer|date= 2016|series= Metal Ions in Life Sciences|volume=16|title= The Alkali Metal Ions: Their Role in Life|editor1-last=Astrid|editor1-first= Sigel|editor2-last=Helmut|editor2-first=Sigel|editor3-last=Roland K.O.|editor3-first= Sigel|chapter= Chapter 8. Sodium and Potassium Ions in Proteins and Enzyme Catalysis |pages= 259–290
|doi=10.1007/978-3-319-21756-7_8|pmid= 26860304|isbn= 978-3-319-21755-0}}</ref> Potassium is largely intracellular.<ref>{{Cite journal |last1=Zacchia |first1=Miriam |last2=Abategiovanni |first2=Maria Luisa |last3=Stratigis |first3=Spiros |last4=Capasso |first4=Giovambattista |date=2016 |title=Potassium: From Physiology to Clinical Implications |journal=Kidney Diseases |language=en |volume=2 |issue=2 |pages=72–79 |doi=10.1159/000446268 |pmid=27536695 |issn=2296-9381|pmc=4947686 }}</ref>

===Biochemical function===
Potassium levels influence multiple physiological processes, including<ref>{{cite book|vauthors=Weiner ID, Linus S, Wingo CS|chapter= Disorders of potassium metabolism|veditors= Freehally J, Johnson RJ, Floege J|title= Comprehensive clinical nephrology|edition= 5th |place=St. Louis|publisher= Saunders|year= 2014|pages=118|isbn= 978-0-323-24287-5 }}</ref><ref>{{cite book|vauthors=Malnic G, Giebisch G, Muto S, Wang W, Bailey MA, Satlin LM|chapter= Regulation of K+ excretion|veditors= Alpern RJ, Caplan MJ, Moe OW|title=Seldin and Giebisch's the kidney: physiology and pathophysiology|edition= 5th |place= London|publisher= Academic Press|year= 2013|pages=1659–1716|isbn=978-0-12-381463-0 }}</ref><ref>{{cite book |vauthors=Mount DB, Zandi-Nejad K |chapter=Disorders of potassium balance |veditors= Taal MW, Chertow GM, Marsden PA, Skorecki KL, Yu AS, Brenner BM |title=The kidney |edition= 9th |place= Philadelphia |publisher= Elsevier |year= 2011 |pages=640–688 |isbn=978-1-4557-2304-1 }}</ref>
*resting cellular-membrane potential and the propagation of action potentials in neuronal, muscular, and cardiac tissue. Due to the electrostatic and chemical properties, {{chem2|K+}} ions are larger than {{chem2|Na+}} ions, and ion channels and pumps in cell membranes can differentiate between the two ions, actively pumping or passively passing one of the two ions while blocking the other.<ref>{{cite journal|pmid=17472437|title=Structural and thermodynamic properties of selective ion binding in a K+ channel|last1=Lockless |first1 = S. W.| last2= Zhou|first2 =M.|last3= MacKinnon|first3 =R.|journal=PLOS Biol|year= 2007 |volume=5|issue=5|page=e121|doi=10.1371/journal.pbio.0050121|pmc=1858713 |doi-access=free }}</ref>
*hormone secretion and action
*vascular tone
*systemic blood pressure control
*gastrointestinal motility
*acid–base homeostasis
*glucose and insulin metabolism
*mineralocorticoid action
*renal concentrating ability
*fluid and electrolyte balance
*local cortical monoaminergic norepinephrine, serotonin, and dopamine levels, and through them, sleep/wake balance, and spontaneous activity.<ref name="Dietz Weikop Hauglund Andersen 2023 p.">{{cite journal |last1=Dietz |first1=Andrea Grostøl |last2=Weikop |first2=Pia |last3=Hauglund |first3=Natalie |last4=Andersen |first4=Mie |last5=Petersen |first5=Nicolas Caesar |last6=Rose |first6=Laura |last7=Hirase |first7=Hajime |last8=Nedergaard |first8=Maiken |date=2023 |title=Local extracellular K <sup>+</sup> in cortex regulates norepinephrine levels, network state, and behavioral output |journal=Proceedings of the National Academy of Sciences |volume=120 |issue=40 |page=e2305071120 |doi=10.1073/pnas.2305071120 |issn=0027-8424|doi-access=free |pmid=37774097 |pmc=10556678 |bibcode=2023PNAS..12005071D }}</ref>

===Homeostasis===
Potassium homeostasis denotes the maintenance of the total body potassium content, plasma potassium level, and the ratio of the intracellular to extracellular potassium concentrations within narrow limits, in the face of pulsatile intake (meals), obligatory renal excretion, and shifts between intracellular and extracellular compartments.

====Plasma levels====
Plasma potassium is normally kept at 3.5 to 5.5 millimoles (mmol) [or milliequivalents (mEq)] per liter by multiple mechanisms.<ref name="Wei Gritter Vogt de Borst 2020 pp. 952–968">{{cite journal | last1=Wei | first1=Kuang-Yu | last2=Gritter | first2=Martin | last3=Vogt | first3=Liffert | last4=de Borst | first4=Martin H | last5=Rotmans | first5=Joris I | last6=Hoorn | first6=Ewout J | title=Dietary potassium and the kidney: lifesaving physiology | journal=Clinical Kidney Journal | publisher=Oxford University Press (OUP) | volume=13 | issue=6 | date=2020-09-02 | issn=2048-8513 | pmid=33391739 | pmc=7769543 | doi=10.1093/ckj/sfaa157 | pages=952–968}}</ref> Levels outside this range are associated with an increasing rate of death from multiple causes,<ref>{{cite journal | last1 = Goyal | first1 = Abhinav | last2 = Spertus | first2 = John A. | last3 = Gosch | first3 = Kensey | last4 = Venkitachalam | first4 = Lakshmi | last5 = Jones | first5 = Philip G. | last6 = Van den Berghe | first6 = Greet | last7 = Kosiborod | first7 = Mikhail | year = 2012 | title = Serum Potassium Levels and Mortality in Acute Myocardial Infarction | journal = JAMA | volume = 307 | issue = 2| pages = 157–164 | doi = 10.1001/jama.2011.1967 | pmid = 22235086 | doi-access = free }}</ref> and some cardiac, kidney,<ref>{{cite journal | last1 = Smyth | first1 = A. | last2 = Dunkler | first2 = D. | last3 = Gao | first3 = P. | display-authors = etal | year = 2014 | title = The relationship between estimated sodium and potassium excretion and subsequent renal outcomes | journal = Kidney Int | volume = 86 | issue = 6| pages = 1205–1212 | doi=10.1038/ki.2014.214| pmid = 24918156 | doi-access = free }}</ref> and lung diseases progress more rapidly if serum potassium levels are not maintained within the normal range.

An average meal of 40–50{{nbsp}}mmol presents the body with more potassium than is present in all plasma (20–25{{nbsp}}mmol). This surge causes the plasma potassium to rise up to 10% before clearance by renal and extrarenal mechanisms.<ref>{{cite journal | last1 = Moore-Ede | first1 = M. C. | year = 1986 | title = Physiology of the circadian timing system: predictive versus reactive homeostasis | journal = Am J Physiol | volume = 250 | issue = 5 Pt 2| pages = R737–R752 | doi = 10.1152/ajpregu.1986.250.5.R737 | pmid = 3706563 }}</ref>

[[Hypokalemia]], a deficiency of potassium in the plasma, can be fatal if severe. Common causes are increased gastrointestinal loss ([[vomiting]], [[diarrhea]]), and increased renal loss ([[polyuria|diuresis]]).<ref>{{cite book|publisher=Lippincott Williams & Wilkins|chapter-url = https://books.google.com/books?id=_XavFllbnS0C&pg=PA812|page = 812| chapter = Potassium|title = Pediatric critical care medicine|isbn = 978-0-7817-9469-5|last1 = Slonim|first1= Anthony D.|last2 = Pollack|first2= Murray M.|date = 2006}}</ref> Deficiency symptoms include muscle weakness, [[paralytic ileus]], ECG abnormalities, decreased reflex response; and in severe cases, respiratory paralysis, [[alkalosis]], and [[cardiac arrhythmia]].<ref>{{cite book |chapter-url = https://books.google.com/books?id=c4xAdJhIi6oC&pg=PT257 |page =257|chapter = hypokalemia |title = Essentials of Nephrology|edition=2nd|publisher=BI Publications |isbn = 978-81-7225-323-3 |last1 = Visveswaran |first1= Kasi |date = 2009}}</ref>

====Control mechanisms====
Potassium content in the plasma is tightly controlled by four basic mechanisms, which have various names and classifications. These are:
# a reactive negative-feedback system,
# a reactive feed-forward system,
# a predictive or [[circadian]] system, and
# an internal or cell membrane transport system.
Collectively, the first three are sometimes termed the "external potassium homeostasis system";<ref>{{cite journal |last1=Gumz |first1=Michelle L. |last2=Rabinowitz |first2=Lawrence |last3=Wingo |first3=Charles S. |date=2015-07-02 |title=An Integrated View of Potassium Homeostasis |journal=The New England Journal of Medicine |volume=373 |issue=1 |pages=60–72 |doi=10.1056/NEJMra1313341 |issn=0028-4793 |pmc=5675534 |pmid=26132942}}</ref> and the first two, the "reactive potassium homeostasis system".
* The reactive negative-feedback system refers to the system that induces renal secretion of potassium in response to a rise in the plasma potassium (potassium ingestion, shift out of cells, or intravenous infusion.)
* The reactive feed-forward system refers to an incompletely understood system that induces renal potassium secretion in response to potassium ingestion prior to any rise in the plasma potassium. This is probably initiated by gut cell potassium receptors that detect ingested potassium and trigger [[vagal]] [[afferent nerve fiber|afferent]] signals to the pituitary gland.
* The predictive or circadian system increases renal secretion of potassium during mealtime hours (e.g. daytime for humans, nighttime for rodents) independent of the presence, amount, or absence of potassium ingestion. It is mediated by a [[circadian oscillator]] in the [[suprachiasmatic nucleus]] of the brain (central clock), which causes the kidney (peripheral clock) to secrete potassium in this rhythmic circadian fashion.[[File:Scheme sodium-potassium pump-en.svg|thumb|right|upright=1.8|The action of the [[sodium-potassium pump]] is an example of primary [[active transport]]. The two carrier proteins embedded in the cell membrane on the left are using [[Adenosine triphosphate|ATP]] to move sodium out of the cell against the concentration gradient; The two proteins on the right are using secondary active transport to move potassium into the cell. This process results in reconstitution of ATP.]]
* The ion transport system moves potassium across the cell membrane using two mechanisms. One is active and pumps sodium out of, and potassium into, the cell. The other is passive and allows potassium to leak out of the cell. Potassium and sodium cations influence fluid distribution between intracellular and extracellular compartments by [[osmotic]] forces. The movement of potassium and sodium through the cell membrane is mediated by the [[Na⁺/K⁺-ATPase]] pump.<ref>{{cite book|last=Campbell|first=Neil|title=Biology|date=1987|isbn=978-0-8053-1840-1|page=795|publisher=Benjamin/Cummings Pub. Co.|location=Menlo Park, California}}</ref> This [[Ion transporter|ion pump]] uses [[Adenosine triphosphate|ATP]] to pump three sodium ions out of the cell and two potassium ions into the cell, creating an electrochemical gradient and electromotive force across the cell membrane. The highly selective [[potassium ion channels]] (which are [[tetramer]]s) are crucial for [[Hyperpolarization (biology)|hyperpolarization]] inside [[neuron]]s after an action potential is triggered, to cite one example. The most recently discovered potassium ion channel is KirBac3.1, which makes a total of five potassium ion channels (KcsA, KirBac1.1, KirBac3.1, KvAP, and MthK) with a determined structure. All five are from [[prokaryotic]] species.<ref name="pmid16253415">{{cite journal|first1=Mikko |last1 = Hellgren| first2= Lars |last2= Sandberg|first3= Olle |last3= 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=Biophysical Chemistry| volume=120|issue=1|pages=1–9|year=2006|pmid=16253415|doi=10.1016/j.bpc.2005.10.002}}</ref>

====Renal filtration, reabsorption, and excretion====
Renal handling of potassium is closely connected to sodium handling. Potassium is the major cation (positive ion) inside animal cells (150{{nbsp}}mmol/L, 4.8{{nbsp}}g/L), while sodium is the major cation of [[extracellular fluid]] (150{{nbsp}}mmol/L, 3.345{{nbsp}}g/L). In the kidneys, about 180{{nbsp}}liters of plasma is filtered through the [[Glomerulus (kidney)|glomeruli]] and into the [[renal tubules]] per day.<ref name="Potts1964">{{cite book |author=Potts, W. T. W. |author2=Parry, G. |date=1964 |title=Osmotic and ionic regulation in animals |publisher=[[Pergamon Press]]}}</ref> This filtering involves about 600{{nbsp}}mg of sodium and 33{{nbsp}}mg of potassium. Since only 1–10{{nbsp}}mg of sodium and 1–4{{nbsp}}mg of potassium are likely to be replaced by diet, renal filtering must efficiently reabsorb the remainder from the plasma.

Sodium is reabsorbed to maintain extracellular volume, osmotic pressure, and serum sodium concentration within narrow limits. Potassium is reabsorbed to maintain serum potassium concentration within narrow limits.<ref>{{cite journal |last1=Lans |first1=H. 's. |last2= Stein |first2=I. F. |last3= Meyer |first3=K. A. |title=The relation of serum potassium to erythrocyte potassium in normal subjects and patients with potassium deficiency |journal=American Journal of the Medical Sciences |volume=223 |issue=1 |pages=65–74 |year=1952| pmid=14902792 |doi=10.1097/00000441-195201000-00011}}</ref> [[Sodium pump]]s in the renal tubules operate to reabsorb sodium. Potassium must be conserved, but because the amount of potassium in the blood plasma is very small and the pool of potassium in the cells is about 30 times as large, the situation is not so critical for potassium. Since potassium is moved passively<ref>{{cite journal |last1=Bennett |first1=C. M. |last2= Brenner |first2=B. M. |last3= Berliner |first3=R. W. |title=Micropuncture study of nephron function in the rhesus monkey |journal=Journal of Clinical Investigation |volume=47 |issue=1 |pages=203–216 |year=1968 |pmid=16695942 |doi=10.1172/JCI105710 |pmc=297160}}</ref><ref>{{cite journal |last1=Solomon |first1=A. K. |title=Pumps in the living cell |journal=Scientific American| volume=207 |pages=100–8 |year=1962 |pmid=13914986 |doi=10.1038/scientificamerican0862-100 |issue=2 |bibcode=1962SciAm.207b.100S}}</ref> in counter flow to sodium in response to an apparent (but not actual) [[Donnan equilibrium]],<ref>{{cite book |last=Kernan |first= Roderick P. |title=Cell potassium (Transport in the life sciences) |publisher=[[John Wiley & Sons|Wiley]] |location=New York |date=1980 |pages=40, 48 |isbn= 978-0-471-04806-0}}</ref> the urine can never sink below the concentration of potassium in serum except sometimes by actively excreting water at the end of the processing. Potassium is excreted twice and reabsorbed three times before the urine reaches the collecting tubules.<ref>{{cite journal |last1=Wright |first1=F. 's. |title=Sites and mechanisms of potassium transport along the renal tubule |journal=Kidney International |volume=11 |issue=6 |pages=415–432 |year=1977 |pmid=875263 |doi=10.1038/ki.1977.60 |doi-access=free}}</ref> At that point, urine usually has about the same potassium concentration as plasma. At the end of the processing, potassium is secreted one more time if the serum levels are too high.{{citation needed|date=August 2017}}

With no potassium intake, it is excreted at about 200{{nbsp}}mg per day until, in about a week, potassium in the serum declines to a mildly deficient level of 3.0–3.5{{nbsp}}mmol/L.<ref>{{cite journal |last1=Squires |first1=R. D. |last2= Huth |first2 = E. J. |title=Experimental potassium depletion in normal human subjects. I. Relation of ionic intakes to the renal conservation of potassium |journal=Journal of Clinical Investigation |volume=38 |issue=7 |pages=1134–48 |year=1959 |pmid=13664789 |doi=10.1172/JCI103890 |pmc=293261}}</ref> If potassium is still withheld, the concentration continues to fall until a severe deficiency causes eventual death.<ref>{{cite book |author=Fiebach, Nicholas H. |author2=Barker, Lee Randolph |author3=Burton, John Russell |author4=Zieve, Philip D.|title=Principles of ambulatory medicine |url=https://books.google.com/books?id=UGVylX6g4i8C&pg=PA748 |date=2007 |publisher=Lippincott Williams & Wilkins |isbn=978-0-7817-6227-4 |pages=748–750}}</ref>

The potassium moves passively through pores in the cell membrane. When ions move through [[ion transporter]]s (pumps) there is a gate in the pumps on both sides of the cell membrane and only one gate can be open at once. As a result, approximately 100 ions are forced through per second. [[Ion channel]]s have only one gate, and there only one kind of ion can stream through, at 10 million to 100 million ions per second.<ref>{{cite journal |last=Gadsby |first=D. C. |title=Ion transport: spot the difference |journal=Nature |volume=427 |issue=6977 |pages=795–7 |year=2004 |pmid=14985745 |doi=10.1038/427795a |bibcode = 2004Natur.427..795G |s2cid=5923529}}; for a diagram of the potassium pores are viewed, see {{cite journal |author=Miller, C |title=See potassium run |journal=Nature |volume=414 |issue=6859 |pages=23–24 |year=2001 |pmid=11689922 |doi=10.1038/35102126 |bibcode = 2001Natur.414...23M |s2cid=4423041 }}</ref> Calcium is required to open the pores,<ref>{{cite journal |last1=Jiang |first1=Y. |last2=Lee |first2=A. |last3=Chen |first3=J. |last4=Cadene |first4=M. |last5=Chait |first5=B. 't. |last6=Mackinnon |first6=R. |url=http://einstein.ciencias.uchile.cl/CursoTroncal2007/Biblio/Jiang__MacKinnonNature417_515_2002.pdf |title=Crystal structure and mechanism of a calcium-gated potassium channel |journal=Nature |volume=417 |issue=6888 |pages=515–22 |year=2002 |pmid=12037559 |doi=10.1038/417515a |bibcode=2002Natur.417..515J |s2cid=205029269 |url-status=dead |archive-url=https://web.archive.org/web/20090424074015/http://einstein.ciencias.uchile.cl/CursoTroncal2007/Biblio/Jiang__MacKinnonNature417_515_2002.pdf |archive-date=2009-04-24 |s2cid-access=free }}</ref> although calcium may work in reverse by blocking at least one of the pores.<ref>{{cite journal |last1=Shi |first1=N. |last2= Ye |first2=S. |last3= Alam |first3=A. |last4= Chen |first4=L. |last5= Jiang |first5=Y. |title=Atomic structure of a Na<sup>+</sup>- and K<sup>+</sup>-conducting channel |journal=Nature |volume=440 |issue=7083 |pages=570–4 |year=2006 |pmid=16467789 |doi=10.1038/nature04508 |bibcode =2006Natur.440..570S |s2cid=4355500 |postscript=;}} includes a detailed picture of atoms in the pump.</ref> Carbonyl groups inside the pore on the amino acids mimic the water hydration that takes place in water solution<ref>{{cite journal |last1=Zhou |first1=Y. |last2= Morais-Cabral |first2=J. H. |last3= Kaufman |first3=A. |last4= MacKinnon |first4=R. |title=Chemistry of ion coordination and hydration revealed by a K<sup>+</sup> channel-Fab complex at 2.0 A resolution |journal=Nature |volume=414 |issue=6859 |pages=43–48 |year=2001 |pmid=11689936 |doi=10.1038/35102009 |bibcode = 2001Natur.414...43Z |s2cid=205022645 |url=http://www.acsu.buffalo.edu/~moralesm/Zhou.pdf |url-status=dead |archive-url=https://web.archive.org/web/20211017203255/http://www.acsu.buffalo.edu/~moralesm/Zhou.pdf |archive-date= Oct 17, 2021 }}</ref> by the nature of the electrostatic charges on four carbonyl groups inside the pore.<ref>{{cite journal|last1=Noskov |first1=S. Y. |last2= Bernèche |first2=S. |last3= Roux |first3=B. |title=Control of ion selectivity in potassium channels by electrostatic and dynamic properties of carbonyl ligands |journal=Nature |volume=431 |issue=7010 |pages=830–4 |year=2004 |pmid=15483608 |doi=10.1038/nature02943 |bibcode =2004Natur.431..830N |s2cid=4414885 |s2cid-access=free |url=https://www.physics.uci.edu/~tritz/BP/ionchannel.pdf |url-status=live |archive-url=https://web.archive.org/web/20230326185426/https://www.physics.uci.edu/~tritz/BP/ionchannel.pdf |archive-date= Mar 26, 2023 }}</ref>

===Nutrition===

====Dietary recommendations====
===== North America =====
The U.S. [[National Academy of Medicine]] (NAM), on behalf of both the U.S. and Canada, sets [[Dietary Reference Intake]]s, including Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs), or [[Adequate Intake]]s (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 level]]s (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 |access-date=2019-05-13 |archive-date=2019-05-13 |archive-url=https://web.archive.org/web/20190513200758/https://www.nap.edu/read/25353/chapter/8 |url-status=live }}</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 |archive-date=May 9, 2019 |archive-url=https://web.archive.org/web/20190509031658/http://www.nationalacademies.org/hmd/Reports/2019/dietary-reference-intakes-sodium-potassium.aspx |url-status=live }}</ref>

As of 2004, most Americans adults consume less than 3,000{{nbsp}}mg.<ref name="iom_panel2005">{{cite book|author=Panel on Dietary Reference Intakes for Electrolytes and Water, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition|title=DRI, dietary reference intakes for water, potassium, sodium, chloride, and sulfate|date=2004|publisher=National Academies Press|location=Washington, D.C.|isbn=978-0-309-53049-1|url=http://www.iom.edu/Reports/2004/Dietary-Reference-Intakes-Water-Potassium-Sodium-Chloride-and-Sulfate.aspx|url-status=dead|archive-url=https://web.archive.org/web/20111006174858/http://www.iom.edu/Reports/2004/Dietary-Reference-Intakes-Water-Potassium-Sodium-Chloride-and-Sulfate.aspx|archive-date=2011-10-06}}</ref>

===== Europe =====
Likewise, in the European Union, in particular in Germany, and Italy, insufficient potassium intake is somewhat common.<ref>{{cite journal|last=Karger|first=S.|journal=Annals of Nutrition and Metabolism|year=2004|volume=48|issue=2 (suppl) |pages=1–16 |title=Energy and nutrient intake in the European Union|doi=10.1159/000083041|doi-access=free}}</ref> 

The [[National Health Service]] in the United Kingdom recommends a similar intake, saying that "adults (19 to 64 years) need {{val|3500|u=mg}} per day" and that excess amounts may cause health problems such as stomach pain and [[diarrhea]].<ref>{{cite web | title=Vitamins and minerals | website=[[National Health Service]] (NHS) | date=18 November 2021 | url=https://www.nhs.uk/conditions/vitamins-and-minerals/others/ | access-date=13 November 2022 | archive-date=3 April 2019 | archive-url=https://web.archive.org/web/20190403142101/https://www.nhs.uk/conditions/vitamins-and-minerals/others/ | url-status=live }}</ref>

====Food sources====
Potassium is present in all fruits, vegetables, meat and fish. Foods with high potassium concentrations include [[Yam (vegetable)|yam]], [[parsley]], dried [[apricot]]s, [[milk]], [[chocolate]], all [[nut (fruit)|nuts]] (especially [[almond]]s and [[pistachio]]s), [[potato]]es, [[bamboo shoot]]s, [[banana]]s, [[avocado]]s, [[coconut water]], [[soybean]]s, and [[bran]].<ref>{{cite web| url = http://apjcn.nhri.org.tw/server/info/books-phds/books/foodfacts/html/data/data5b.html|title = Potassium Food Charts|publisher =Asia Pacific Journal of Clinical Nutrition|access-date = 2011-05-18|archive-url=https://web.archive.org/web/20210429215547/http://apjcn.nhri.org.tw/server/info/books-phds/books/foodfacts/html/data/data5b.html|archive-date=2021-04-29}}</ref>

The  [[United States Department of Agriculture]] also lists [[tomato paste]], [[orange juice]], [[beet greens]], [[white beans]], [[Cooking banana|plantains]], and many other dietary sources of potassium, ranked in descending order according to potassium content. A day's worth of potassium is in 5 plantains or 11 bananas.<ref>{{cite news|title=Potassium Content of Selected Foods per Common Measure, sorted by nutrient content |publisher=USDA National Nutrient Database for Standard Reference, Release 20 |url=http://www.nal.usda.gov/fnic/foodcomp/Data/SR20/nutrlist/sr20w306.pdf |url-status=dead |archive-url=https://web.archive.org/web/20081217043521/http://www.nal.usda.gov/fnic/foodcomp/Data/SR20/nutrlist/sr20w306.pdf |archive-date=December 17, 2008 }}</ref>

====Deficient intake====
{{main|Hypokalemia}}
Mild hypokalemia does not cause distinct symptoms acting instead as a risk factor for [[hypertension]]<ref>{{cite journal |vauthors=Whelton PK, He J, Cutler JA, Brancati FL, Appel LJ, Follmann D, Klag MJ |title=Effects of oral potassium on blood pressure. Meta-analysis of randomized controlled clinical trials |journal=JAMA |volume=277 |issue=20 |pages=1624–32 |year=1997 |pmid=9168293 |doi=10.1001/jama.1997.03540440058033 |s2cid=25937399 }}</ref><ref name=":0">{{cite journal | last1 = Krishna | first1 = GG | last2 = Miller | first2 = E | last3 = Kapoor | first3 = S | title = Increased blood pressure during potassium depletion in normotensive men | journal = The New England Journal of Medicine | volume = 320 | issue = 18 | pages = 1177–82 | year = 1989 | pmid = 2624617| doi = 10.1056/NEJM198905043201804 }}</ref> and [[cardiac arrhythmia]].<ref name=EU2010>{{cite journal|last1=Soar| first1=J|last2=Perkins|first2=GD| last3=Abbas|first3=G|last4=Alfonzo|first4=A|last5=Barelli| first5=A|last6=Bierens|first6=JJ| last7=Brugger|first7=H|last8=Deakin|first8=CD|last9=Dunning|first9=J|last10=Georgiou|first10=M| last11=Handley|first11=AJ|last12=Lockey| first12=DJ|last13=Paal|first13=P|last14=Sandroni|first14=C| last15=Thies|first15=KC|last16=Zideman|first16=DA|last17=Nolan|first17=JP|title=European Resuscitation Council Guidelines for Resuscitation 2010 Section 8. Cardiac arrest in special circumstances: Electrolyte abnormalities, poisoning, drowning, accidental hypothermia, hyperthermia, asthma, anaphylaxis, cardiac surgery, trauma, pregnancy, electrocution.|journal=Resuscitation|date=October 2010| volume=81|issue=10|pages=1400–33|pmid=20956045| doi=10.1016/j.resuscitation.2010.08.015}}</ref>
Severe hypokalemia usually presents with [[hypertension]], [[arrhythmia]], [[muscle cramps]], [[fatigue (medical)|fatigue]], [[weakness]] and [[constipation]].<ref name=EU2010/>
Causes of hypokalemia include vomiting, [[diarrhea]], medications like [[furosemide]] and [[steroid]]s, [[Kidney dialysis|dialysis]], [[diabetes insipidus]], [[hyperaldosteronism]], [[hypomagnesemia]].<ref name=EU2010/>

====Supplementation====
Supplements of potassium are most widely used in conjunction with [[diuretic]]s that block reabsorption of sodium and water upstream from the [[distal tubule]] ([[thiazide]]s and [[loop diuretics]]), because this promotes increased distal tubular potassium secretion, with resultant increased potassium excretion.<ref>{{Cite journal |last1=Horisberger |first1=Jean-Daniel |last2=Giebisch |first2=Gerhard |date=1987 |title=Potassium-Sparing Diuretics |url=https://karger.com/KBR/article/doi/10.1159/000173130 |journal=Kidney and Blood Pressure Research |language=en |volume=10 |issue=3–4 |pages=198–220 |doi=10.1159/000173130 |pmid=2455308 |issn=1420-4096 |archive-date=2024-07-12 |access-date=2024-07-19 |archive-url=https://web.archive.org/web/20240712015613/https://karger.com/KBR/article/doi/10.1159/000173130 |url-status=dead }}</ref> A variety of prescription and over-the counter supplements are available.<ref>{{Cite web |last1=Ng |first1=Kimberly |last2=Lee |first2=Chung-Shie |date=February 16, 2017 |title=Updated Treatment Options in the Management of Hyperkalemia |url=https://www.uspharmacist.com/article/updated-treatment-options-in-the-management-of-hyperkalemia |access-date=2024-07-19 |website=US Pharmacist |language=en}}</ref> Potassium chloride may be dissolved in water, but the salty/bitter taste makes liquid supplements unpalatable.<ref name="bitter" /><ref>{{Cite journal |last1=Benge |first1=Cassandra D. |last2=Burka |first2=Abigail T. |date=2020 |title=Oral Liquid Potassium Chloride Dosing Pathway in a Tertiary Care Veteran Affairs Academic Medical Center |url=https://journals.lww.com/10.1097/HPC.0000000000000197 |journal=Critical Pathways in Cardiology: A Journal of Evidence-Based Medicine |language=en |volume=19 |issue=1 |pages=18–21 |doi=10.1097/HPC.0000000000000197 |pmid=31478945 |issn=1535-282X}}</ref>  Potassium is also available in tablets or capsules, which are formulated to allow potassium to leach slowly out of a matrix, since very high concentrations of potassium ion that occur adjacent to a solid tablet can injure the gastric or intestinal mucosa.<ref name=BNF69/><ref>{{Cite journal |last1=Gueta |first1=Itai |last2=Markovits |first2=Noa |last3=Halkin |first3=Hillel |last4=Loebstein |first4=Ronen |date=2021 |title=Concomitant oral potassium chloride and anticholinergic therapy is associated with upper gastrointestinal bleeding: A cohort study |url=https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bcp.14616 |journal=British Journal of Clinical Pharmacology |language=en |volume=87 |issue=4 |pages=2064–2069 |doi=10.1111/bcp.14616 |pmid=33068044 |issn=0306-5251}}</ref> For this reason, non-prescription potassium pills are limited by law in the US to a maximum of 99{{nbsp}}mg of potassium.<ref>{{Cite web |date=June 2, 2022 |title=Potassium - Fact Sheet for Health Professionals |url=https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/ |access-date=2024-07-19 |website=National Institutes of Health (NIH) Office of Dietary Supplements (ODS) |language=en}}</ref>

Potassium supplementation can also be combined with other metabolites, such as citrate or chloride, to achieve specific clinical effects.<ref name="pmid38333496">{{cite journal |vauthors=Keller CL, Jones NT, Abadie RB, Barham W, Behara R, Patil S, Paladini A, Ahmadzadeh S, Shekoohi S, Varrassi G, Kaye AD |title=Non-steroidal Anti-inflammatory Drug (NSAID)-, Potassium Supplement-, Bisphosphonate-, and Doxycycline-Mediated Peptic Ulcer Effects: A Narrative Review |journal=Cureus |volume=16 |issue=1 |pages=e51894 |date=January 2024 |pmid=38333496 |pmc=10849936 |doi=10.7759/cureus.51894 |doi-access=free |url=}}</ref>

Potassium supplements may be employed to mitigate the impact of hypertension, thereby reducing cardiovascular risk.<ref>{{cite journal |last1=D'Elia |first1=L. |last2=Barba |first2=G. |last3=Cappuccio |first3=F. |last4=Strazzullo |year=2011 |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 |doi=10.1016/j.jacc.2010.09.070 |pmid=21371638|doi-access=free }}</ref> [[Potassium chloride]] and [[potassium bicarbonate]] may be useful to control mild [[hypertension]].<ref>{{cite journal |vauthors=He FJ, Marciniak M, Carney C, Markandu ND, Anand V, Fraser WD, Dalton RN, Kaski JC, MacGregor GA |title=Effects of potassium chloride and potassium bicarbonate on endothelial function, cardiovascular risk factors, and bone turnover in mild hypertensives |journal=Hypertension |volume=55 |issue=3 |pages=681–8 |year=2010 |pmid=20083724 |doi=10.1161/HYPERTENSIONAHA.109.147488 |doi-access=free }}</ref> In 2020, potassium was the 33rd most commonly prescribed medication in the U.S., with more than 17{{nbsp}}million prescriptions.<ref>{{cite web |title=The Top 300 of 2020 |url=https://clincalc.com/DrugStats/Top300Drugs.aspx |website=ClinCalc |access-date=7 October 2022 |archive-date=12 February 2021 |archive-url=https://web.archive.org/web/20210212142534/https://clincalc.com/DrugStats/Top300Drugs.aspx |url-status=live }}</ref><ref>{{cite web | title=Potassium Chloride - Drug Usage Statistics | website=ClinCalc | url=https://clincalc.com/DrugStats/Drugs/PotassiumChloride | access-date=7 October 2022 | archive-date=8 October 2022 | archive-url=https://web.archive.org/web/20221008035439/https://clincalc.com/DrugStats/Drugs/PotassiumChloride | url-status=live }}</ref> Potassium supplementation has been shown to reduce both systolic and diastolic blood pressure in individuals with essential hypertension.<ref name="pmid38333496"/>

Additionally, potassium supplements may be employed with the aim of preventing the formation of kidney stones, a condition that can lead to renal complications if left untreated. Low potassium levels can lead to decreased calcium reabsorption in the kidneys, increasing the risk of elevated urine calcium and the formation of kidney stones. By maintaining adequate potassium levels, this risk can be reduced.<ref name="pmid38333496"/> 

The mechanism of action of potassium involves various types of transporters and channels that facilitate its movement across cell membranes. This process can lead to an increase in the pumping of hydrogen ions. This, in turn, can escalate the production of gastric acid, potentially contributing to the development of gastric ulcers.<ref name="pmid38333496"/> 

Potassium has a role in bone health. It contributes to the acid-base equilibrium in the body and helps protect bone tissue. Potassium salts produce an alkaline component that can aid in maintaining bone health.<ref name="pmid38333496"/>

For individuals with diabetes, potassium supplementation may be necessary, particularly for those with type 2 diabetes. Potassium is essential for the secretion of insulin by pancreatic beta cells, which helps regulate glucose levels. Without sufficient potassium, insulin secretion is compromised, leading to hyperglycemia and worsening diabetes.<ref name="pmid38333496"/>

Excessive potassium intake can have adverse effects, such as gastrointestinal discomfort and disturbances in heart rhythm.<ref name="pmid38333496"/>

Potassium supplementation can have side effects on ulceration, particularly in relation to peptic ulcer disease. Potassium channels have the potential to increase gastric acid secretion, which can lead to an increased risk of ulcerations. Medications used for peptic ulcer disease, known as "proton pump inhibitors", work by inhibiting potassium pumps that activate the H/K ATPase. This inhibition helps to reduce the secretion of hydrochloric acid into the parietal cell, thereby decreasing acidic synthesis and lowering the risk of ulcers. Nicorandil, a drug used for the treatment of ischemic heart disease, can stimulate nitrate and potassium ATP channels, and as a result, it has been associated with side effects such as GI, oral, and anal ulcers. Potassium chloride tablets are specifically associated with pill esophagitis.<ref>{{Cite journal |last1=Abdi |first1=Saeed |last2=Masbough |first2=Farnoosh |last3=Nazari |first3=Maryam |last4=Abbasinazari |first4=Mohammad |date=2022-06-20 |title=Drug-induced esophagitis and helpful management for healthcare providers |url=https://doi.org/10.22037/ghfbb.v15i3.2591 |journal=Gastroenterology and Hepatology from Bed to Bench |volume=15 |issue=3 |pages=219–224 |doi=10.22037/ghfbb.v15i3.2591 |issn=2008-4234 |pmc=9589134 |pmid=36311965}}</ref> Prolonged and chronic use of potassium supplements has been linked to more severe side effects, including ulcers outside of the gastrointestinal (GI) tract. Close monitoring is necessary for patients who are also taking angiotensinogen-converting enzyme inhibitors, angiotensin receptor blockers, or potassium-sparing diuretics.<ref name="pmid38333496"/>

====Detection by taste buds====
Potassium can be detected by taste because it triggers three of the five types of taste sensations, according to concentration. Dilute solutions of potassium ions taste sweet, allowing moderate concentrations in milk and juices, while higher concentrations become increasingly bitter/alkaline, and finally also salty to the taste. The combined bitterness and saltiness of high-potassium solutions makes high-dose potassium supplementation by liquid drinks a palatability challenge.<ref name="bitter">{{cite book|author1=Institute of Medicine (U.S.). Committee on Optimization of Nutrient Composition of Military Rations for Short-Term, High-Stress Situations|author2=Institute of Medicine (U.S.). Committee on Military Nutrition Research|title=Nutrient composition of rations for short-term, high-intensity combat operations|url=https://books.google.com/books?id=kFatoIBbMboC&pg=PT287|date=2006|publisher=National Academies Press|isbn=978-0-309-09641-6|pages=287–}}</ref><ref>{{cite book|last=Shallenberger|first=R. S. |title=Taste chemistry|url=https://books.google.com/books?id=8_bjyjgClq0C&pg=PA120|date=1993|publisher=Springer|isbn=978-0-7514-0150-9|pages=120–}}</ref> As a food additive, potassium chloride has a salty taste. People wishing to increase their potassium intake or to decrease their sodium intake, after checking with a health professional that it is safe to do so, can substitute potassium chloride for some or all of the sodium chloride (table salt) used in cooking and at the table.<ref>{{Cite journal |last1=Tsai |first1=Yi-Ching |last2=Tsao |first2=Yen-Po |last3=Huang |first3=Chi-Jung |last4=Tai |first4=Yen-Hsuan |last5=Su |first5=Yang-Chin |last6=Chiang |first6=Chern-En |last7=Sung |first7=Shih-Hsien |last8=Chen |first8=Chen-Huan |last9=Cheng |first9=Hao-Min |date=2022 |title=Effectiveness of salt substitute on cardiovascular outcomes: A systematic review and meta-analysis |journal=The Journal of Clinical Hypertension |language=en |volume=24 |issue=9 |pages=1147–1160 |doi=10.1111/jch.14562 |issn=1751-7176 |pmc=9532913 |pmid=36196475}}</ref>