Editing Dietary supplement (section)

===Essential fatty acids===
{{main|Essential fatty acids}}
Fish oil is a commonly used fatty acid supplement because it is a source of [[omega-3 fatty acid]]s.<ref name="NIH">{{cite web|url=http://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/|publisher=US National Institutes of Health, Office of Dietary Supplements|title=Omega-3 Fatty Acids and Health: Fact Sheet for Health Professionals|date=2 November 2016|access-date=5 April 2017}}</ref> Fatty acids are strings of carbon atoms, having a range of lengths. If links are all single (C−C), then the fatty acid is called ''[[saturated fat|saturated]]''; with one double bond (C=C), it is called ''[[monounsaturated fat|monounsaturated]]''; if there are two or more double bonds (C=C=C), it is called ''[[polyunsaturated fat|polyunsaturated]]''. Only two fatty acids, both polyunsaturated, are considered essential to be obtained from the diet, as the others are synthesized in the body. The "essential" fatty acids are [[alpha-linolenic acid]] (ALA), an omega-3 fatty acid, and [[linoleic acid]] (LA), an [[omega-6 fatty acid]].<ref name=NIH/><ref>{{cite book | vauthors = Whitney E, Rolfes SR | chapter = Chapter 5: The Lipids: Triglyerides, Phospholipids, and Sterols | title = Understanding Nutrition | edition = 11th | location = California | publisher = Thomson Wadsworth | year = 2008 | page= 154 | isbn = 978-0-495-11669-1 }}</ref> ALA can be elongated in the body to create other omega-3 fatty acids: [[eicosapentaenoic acid]] (EPA) and [[docosahexaenoic acid]] (DHA).

Plant oils, particularly seed and nut oils, contain ALA.<ref name=NIH/> Food sources of EPA and DHA are oceanic fish, whereas dietary supplement sources include fish oil, krill oil and [[marine algae]] extracts. The [[European Food Safety Authority]] (EFSA) identifies 250&nbsp;mg/day for a combined total of EPA and DHA as Adequate Intake, with a recommendation that women pregnant or lactating consume an additional 100 to 200&nbsp;mg/day of DHA.<ref name=EFSA-Recommended>{{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=August 28, 2017 |df=mdy-all}}</ref> In the United States and Canada are [[Adequate Intake]]s for ALA and LA over various stages of life, but there are no intake levels specified for EPA and/or DHA.<ref name=DRITable>{{cite web | url = http://www.nationalacademies.org/hmd/~/media/Files/Activity%20Files/Nutrition/DRI-Tables/5Summary%20TableTables%2014.pdf?la=en | title = Dietary Reference Intakes (DRIs) | archive-url = https://web.archive.org/web/20180911225459/http://www.nationalacademies.org/hmd/~/media/Files/Activity%20Files/Nutrition/DRI-Tables/5Summary%20TableTables%2014.pdf?la=en | archive-date=2018-09-11 | author = Food and Nutrition Board | publisher = Institute of Medicine, National Academies }}</ref>

Supplementation with EPA and/or DHA does not appear to affect the risk of death, cancer or heart disease.<ref>{{cite journal | vauthors = Rizos EC, Elisaf MS | title = Does Supplementation with Omega-3 PUFAs Add to the Prevention of Cardiovascular Disease? | journal = Current Cardiology Reports | volume = 19 | issue = 6 | page = 47 | date = June 2017 | pmid = 28432658 | doi = 10.1007/s11886-017-0856-8 | s2cid = 23585060 }}</ref><ref name=Mac2006>{{cite journal | vauthors = MacLean CH, Newberry SJ, Mojica WA, Khanna P, Issa AM, Suttorp MJ, Lim YW, Traina SB, Hilton L, Garland R, Morton SC | display-authors = 6 | title = Effects of omega-3 fatty acids on cancer risk: a systematic review | journal = JAMA | volume = 295 | issue = 4 | pages = 403–15 | date = January 2006 | pmid = 16434631 | doi = 10.1001/jama.295.4.403 | hdl-access = free | hdl = 10919/79706 }}</ref> Furthermore, studies of fish oil supplements have failed to support claims of preventing [[Myocardial infarction|heart attacks]] or [[stroke]]s.<ref name="JAMA-201403">{{cite journal | vauthors = Grey A, Bolland M | title = Clinical trial evidence and use of fish oil supplements | journal = JAMA Internal Medicine | volume = 174 | issue = 3 | pages = 460–52 | date = March 2014 | pmid = 24352849 | doi = 10.1001/jamainternmed.2013.12765 | doi-access = free }}</ref> In 2017, the American Heart Association issued a science advisory stating that it could not recommend use of omega-3 fish oil supplements for primary prevention of [[cardiovascular disease]] or stroke, although it reaffirmed supplementation for people who have a history of [[coronary heart disease]].<ref>{{cite journal | vauthors = Siscovick DS, Barringer TA, Fretts AM, Wu JH, Lichtenstein AH, Costello RB, Kris-Etherton PM, Jacobson TA, Engler MB, Alger HM, Appel LJ, Mozaffarian D | display-authors = 6 | title = Omega-3 Polyunsaturated Fatty Acid (Fish Oil) Supplementation and the Prevention of Clinical Cardiovascular Disease: A Science Advisory From the American Heart Association | journal = Circulation | volume = 135 | issue = 15 | pages = e867–e884 | date = April 2017 | pmid = 28289069 | pmc = 6903779 | doi = 10.1161/CIR.0000000000000482 }}</ref>

Manufacturers have begun to include long chain polyunsaturated fatty acids DHA and [[arachidonic acid]] (AA) into their formula milk for newborns, however, a 2017 review found that supplementation with DHA and AA does not appear to be harmful or beneficial to formula-fed infants.<ref>{{cite journal | vauthors = Jasani B, Simmer K, Patole SK, Rao SC | title = Long chain polyunsaturated fatty acid supplementation in infants born at term | journal = The Cochrane Database of Systematic Reviews | volume = 2017 | page = CD000376 | date = March 2017 | issue = 3 | pmid = 28281303 | pmc = 6464574 | doi = 10.1002/14651858.CD000376.pub4 | collaboration = Cochrane Neonatal Group }}</ref>