Editing Nutrient (section)

=== Essential nutrients ===
{{anchor|Essential nutrients}}
An '''essential nutrient''' is a nutrient required for normal physiological function that cannot be synthesized in the body&nbsp;– either at all or in sufficient quantities&nbsp;– and thus must be obtained from a [[Diet (nutrition)|dietary]] source.<ref>{{cite web | url = http://library.med.utah.edu/NetBiochem/nutrition/lect1/2_1.html | title = What is an essential nutrient? | publisher = NetBiochem Nutrition, [[University of Utah]]}}</ref><ref name="VaughanGeissler2009">{{cite book| first1 = John Griffith | last1 = Vaughan | first2 = Catherine | last2 = Geissler| first3 = Barbara | last3 = Nicholson | first4 = Elisabeth | last4 = Dowle | first5 = Elizabeth | last5 = Rice | name-list-style = vanc |title=The new Oxford book of food plants|url=https://books.google.com/books?id=UdKxFcen8zgC&pg=PA212|access-date=13 October 2010|year=2009|publisher=Oxford University Press US|isbn=978-0-19-954946-7|pages=212–}}</ref> Apart from [[water]], which is universally required for the maintenance of [[homeostasis]] in mammals,<ref>{{cite journal | vauthors = Jéquier E, Constant F | title = Water as an essential nutrient: the physiological basis of hydration | journal = European Journal of Clinical Nutrition | volume = 64 | issue = 2 | pages = 115–23 | date = February 2010 | pmid = 19724292 | doi = 10.1038/ejcn.2009.111 | s2cid = 205129670 | url = http://www.nature.com/ejcn/journal/v64/n2/pdf/ejcn2009111a.pdf | doi-access = free }}</ref> essential nutrients are indispensable for various cellular [[metabolic process]]es and for the maintenance and function of tissues and organs.<ref name="AJCN">{{cite journal | vauthors = Chipponi JX, Bleier JC, Santi MT, Rudman D | title = Deficiencies of essential and conditionally essential nutrients | journal = The American Journal of Clinical Nutrition | volume = 35 | issue = 5 Suppl | pages = 1112–6 | date = May 1982 | pmid = 6805293 | doi = 10.1093/ajcn/35.5.1112 | doi-access = free }}</ref> The nutrients considered essential for humans comprise nine amino acids, two fatty acids, thirteen [[vitamin]]s, fifteen [[Mineral (nutrient)|minerals]] and [[choline]].<ref name="AJCN" /> In addition, there are several molecules that are considered conditionally essential nutrients since they are indispensable in certain developmental and pathological states.<ref name="AJCN" /><ref name="Carver">{{cite book |last1=Carver |first1=Jane | name-list-style = vanc |chapter=Conditionally essential nutrients: choline, inositol, taurine, arginine, glutamine and nucleotides |editor1-first=Patti J |editor1-last=Thureen |editor2-first=William W |editor2-last=Hay |title=Neonatal Nutrition and Metabolism |date=2006 |publisher=Cambridge University Press |location=Cambridge, UK|pages=299–311|doi=10.1017/CBO9780511544712.020|isbn=9780511544712}}</ref><ref>{{cite journal | vauthors = Kendler BS | title = Supplemental conditionally essential nutrients in cardiovascular disease therapy | journal = The Journal of Cardiovascular Nursing | volume = 21 | issue = 1 | pages = 9–16 | date = 2006 | pmid = 16407731 | doi = 10.1097/00005082-200601000-00004 | s2cid = 28748412 }}</ref>

====Amino acids====
{{Main|Essential amino acid}}
An essential amino acid is an amino acid that is required by an organism but cannot be synthesized ''[[de novo synthesis|de novo]]'' by it, and therefore must be supplied in its diet. Out of the twenty standard protein-producing amino acids, nine cannot be [[endogenous]]ly synthesized by humans: [[phenylalanine]], [[valine]], [[threonine]], [[tryptophan]], [[methionine]], [[leucine]], [[isoleucine]], [[lysine]], and [[histidine]].<ref>{{cite journal | vauthors = Young VR | title = Adult amino acid requirements: the case for a major revision in current recommendations | journal = The Journal of Nutrition | volume = 124 | issue = 8 Suppl | pages = 1517S–1523S | date = August 1994 | pmid = 8064412 | doi = 10.1093/jn/124.suppl_8.1517S | url = http://jn.nutrition.org/cgi/reprint/124/8_Suppl/1517S.pdf }}</ref><ref name="DRI">{{cite web | title = Dietary Reference Intakes: The Essential Guide to Nutrient Requirements | publisher = Institute of Medicine's Food and Nutrition Board | url = http://fnic.nal.usda.gov/dietary-guidance/dietary-reference-intakes/dri-reports |access-date=14 July 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140705140516/http://fnic.nal.usda.gov/dietary-guidance/dietary-reference-intakes/dri-reports |archive-date=5 July 2014 }}</ref>

====Fatty acids====
{{Main|Essential fatty acid}}
Essential fatty acids (EFAs) are [[fatty acid]]s that humans and other animals must ingest because the body requires them for good health but cannot [[Biosynthesis|synthesize]] them.<ref>{{cite book | title = Modern Nutrition in Health and Disease | edition = 6th | year = 1980 | first1 = Robert S. | last1 = Goodhart | first2 = Maurice E. | last2 = Shils | name-list-style = vanc | publisher = Lea and Febinger | location = Philadelphia | isbn = 978-0-8121-0645-9 | pages = [https://archive.org/details/modernnutritionie6shil/page/134 134–138] | url = https://archive.org/details/modernnutritionie6shil/page/134 }}</ref> Only two fatty acids are known to be essential for humans: [[alpha-linolenic acid]] (an [[omega-3 fatty acid]]) and [[linoleic acid]] (an [[omega-6 fatty acid]]).<ref>{{cite book | vauthors = Ellie W, Rolfes SR | title = Understanding Nutrition | edition = 11th | location = California | publisher = Thomson Wadsworth | year = 2008 | pages = 154}}</ref>

====Vitamins and vitamers====
{{Main|Vitamin}}
Vitamins occur in a variety of related forms known as [[vitamers]]. The vitamers of a given vitamin perform the functions of that vitamin and prevent symptoms of deficiency of that vitamin. Vitamins are those essential organic molecules that are not classified as amino acids or fatty acids. They commonly function as [[enzymatic cofactor]]s, metabolic regulators or [[antioxidant]]s. Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules (e.g. [[vitamin E]] includes [[tocopherol]]s and [[tocotrienol]]s):<ref>{{cite journal | vauthors = Brigelius-Flohé R, Traber MG | title = Vitamin E: function and metabolism | journal = FASEB Journal | volume = 13 | issue = 10 | pages = 1145–55 | date = July 1999 | pmid = 10385606 | doi = 10.1096/fasebj.13.10.1145 | s2cid = 7031925 | doi-access = free }}</ref> vitamins A, C, D, E, K, [[thiamine]] (B<sub>1</sub>), [[riboflavin]] (B<sub>2</sub>), [[Niacin (nutrient)|niacin]] (B<sub>3</sub>), [[pantothenic acid]] (B<sub>5</sub>), [[pyridoxine]] (B<sub>6</sub>), [[biotin]] (B<sub>7</sub>), [[folate]] (B<sub>9</sub>), and [[cobalamin]] (B<sub>12</sub>). The requirement for vitamin D is conditional, as people who get sufficient exposure to ultraviolet light, either from the sun or an artificial source, synthesize vitamin D in the skin.<ref name="lpi">{{cite web |title=Vitamin D |url=https://lpi.oregonstate.edu/mic/vitamins/vitamin-D |publisher=Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis |access-date=14 March 2022 |date=11 February 2021}}</ref>

====Minerals====
{{Main|Mineral (nutrient)}}
Minerals are the [[exogenous]] [[chemical element]]s indispensable for life. Although the four elements [[carbon]], [[hydrogen]], [[oxygen]], and [[nitrogen]] ([[CHON]]) are essential for life, they are so plentiful in food and drink that these are not considered nutrients and there are no recommended intakes for these as minerals. The need for nitrogen is addressed by requirements set for protein, which is composed of nitrogen-containing amino acids. [[Sulfur]] is essential, but again does not have a recommended intake. Instead, recommended intakes are identified for the sulfur-containing amino acids [[methionine]] and [[cysteine]].

The essential nutrient [[trace elements]] for humans, listed in order of [[Reference Daily Intake|recommended dietary allowance]] (expressed as a mass), are [[potassium]], [[chloride]], [[sodium]], [[calcium]], [[phosphorus]], [[magnesium]], [[iron]], [[zinc]], [[manganese]], [[copper]], [[iodine]], [[chromium]], [[molybdenum]], and [[selenium]]. Additionally, [[cobalt]] is a component of vitamin B<sub>12</sub> which is essential. There are other minerals which are essential for some plants and animals, but may or may not be essential for humans, such as [[boron]] and [[silicon]].

====Choline====
{{Main|Choline}}
Choline is an essential nutrient.<ref>{{cite web |title=Dietary Intakes of Choline |url=https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/dbrief/9_choline_intakes_0708.pdf |website=usda.gov |publisher=United States Department of Agriculture |access-date=May 8, 2021}}</ref><ref>{{cite web |title=Choline |url=https://ods.od.nih.gov/factsheets/Choline-HealthProfessional/#:~:text=Choline%20is%20an%20essential%20nutrient,phospholipids%20vital%20for%20cell%20membranes. |website=nih.gov |publisher=National Institutes of Health |access-date=May 8, 2021}}</ref><ref>{{cite journal |last1=Zeisel |first1=Steven H |last2=da Costa |first2=Kerry-Ann |title=Choline: an essential nutrient for public health |journal=Nutrition Reviews |date=November 1, 2009 |volume=67 |issue=11 |pages=615–623 |doi=10.1111/j.1753-4887.2009.00246.x |pmid=19906248 |url= |pmc=2782876 }}</ref> The cholines are a family of water-soluble [[quaternary ammonium compound]]s.<ref name="Choline HMDB">{{cite encyclopedia|title=Choline|url=http://www.hmdb.ca/metabolites/hmdb00097|website=Human Metabolome Database|publisher=The Metabolomics Innovation Centre, University of Alberta, Edmonton, Canada|access-date=13 September 2016|date=17 August 2016}}</ref><ref>Britannica, The Editors of Encyclopaedia. "choline". Encyclopedia Britannica, 11 Dec. 2013, https://www.britannica.com/science/choline. Accessed 17 February 2022.</ref> Choline is the parent compound of the cholines class, consisting of ethanolamine having three methyl substituents attached to the amino function.<ref>National Center for Biotechnology Information (2022). PubChem Compound Summary for CID 305, Choline. Retrieved February 17, 2022 from https://pubchem.ncbi.nlm.nih.gov/compound/Choline.</ref> Healthy humans fed artificially composed diets that are deficient in choline develop fatty liver, liver damage, and muscle damage. Choline was not initially classified as essential because the human body can produce choline in small amounts through phosphatidylcholine metabolism.<ref>{{cite web |title=Choline |url=https://lpi.oregonstate.edu/mic/other-nutrients/choline |website=Micronutrient Information Center |date=28 April 2014 |publisher=Oregon State University |access-date=May 8, 2021}}</ref>