Editing Dietary supplement (section)

==Types==

===Vitamins===
{{main|Vitamin}}
[[File:VitaminSupplementPills.jpg|thumb|right|Pharmacies and supermarkets in the U.S. sell a large variety of vitamin dietary supplements.]]

A vitamin is an [[organic compound]] required by an [[organism]] as a vital [[nutrient]] in limited amounts.<ref name="Lieberman">Lieberman, S and Bruning, N (1990). ''The Real Vitamin & Mineral Book''. NY: Avery Group, 3, {{ISBN|0-89529-769-8}}.</ref> An organic chemical compound (or related set of compounds) is called a vitamin when it cannot be [[biosynthesis|synthesized]] in sufficient quantities by an organism and must be obtained from the diet. The term is conditional both on the circumstances and on the particular organism. For example, [[ascorbic acid]] (vitamin C) is a vitamin for anthropoid primates, [[human]]s, [[guinea pig]]s and [[bat]]s, but not for other mammals. Vitamin D is not an essential nutrient for people who get sufficient exposure to [[Ultraviolet light therapy|ultraviolet light]], either from the sun or an artificial source, as they synthesize vitamin D in skin.<ref>{{cite journal | vauthors = Drouin G, Godin JR, Pagé B | title = The genetics of vitamin C loss in vertebrates | journal = Current Genomics | volume = 12 | issue = 5 | pages = 371–78 | date = August 2011 | pmid = 22294879 | pmc = 3145266 | doi = 10.2174/138920211796429736 }}</ref> Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules, "vitamers", (e.g. vitamin E includes [[tocopherol]]s and [[tocotrienol]]s, vitamin K includes vitamin K<sub>1</sub> and K<sub>2</sub>). The list: vitamins A, C, D, E, K, Thiamine (B<sub>1</sub>), Riboflavin (B<sub>2</sub>), Niacin (B<sub>3</sub>), Pantothenic Acid (B<sub>5</sub>), Vitamin B<sub>6</sub>, Biotin (B<sub>7</sub>), Folate (B<sub>9</sub>) and Vitamin B<sub>12</sub>. Vitamin intake below recommended amounts can result in signs and symptoms associated with vitamin deficiency. There is little evidence of benefit when vitamins are consumed as a dietary supplement by those who are healthy and have a nutritionally adequate diet.<ref name=Fort2013>{{cite journal | vauthors = Fortmann SP, Burda BU, Senger CA, Lin JS, Whitlock EP | title = Vitamin and mineral supplements in the primary prevention of cardiovascular disease and cancer: An updated systematic evidence review for the U.S. Preventive Services Task Force | journal = Annals of Internal Medicine | volume = 159 | issue = 12 | pages = 824–34 | date = December 2013 | pmid = 24217421 | doi = 10.7326/0003-4819-159-12-201312170-00729 | doi-access = free }}</ref>

The [[National Academy of Medicine|U.S. Institute of Medicine]] sets [[tolerable upper intake level]]s (ULs) for some of the vitamins. This does not prevent dietary supplement companies from selling products with content per serving higher than the ULs. For example, the UL for vitamin D is 100&nbsp;μg (4,000 IU),<ref name=IOM>{{citation| title = Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals| publisher = Food and Nutrition Board, Institute of Medicine, National Academies| year = 2004| url = https://www.nal.usda.gov/fnic/dri-tables-and-application-reports| archive-url = https://web.archive.org/web/20170118124310/https://www.nal.usda.gov/fnic/dri-tables-and-application-reports| url-status = dead| archive-date = January 18, 2017| access-date = 2009-06-09}}</ref> but products are available without prescription at 10,000 IU.

===Minerals===
{{main|Mineral (nutrient)}}

Minerals are the [[exogenous]] [[chemical element]]s indispensable for life. Four minerals – [[carbon]], [[hydrogen]], [[oxygen]], and [[nitrogen]] – are essential for life but are so ubiquitous 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 for humans, not identified as having a recommended intake per se. Instead, recommended intakes are identified for the sulfur-containing amino acids [[methionine]] and [[cysteine]]. There are dietary supplements that provide sulfur, such as [[taurine]] and [[methylsulfonylmethane]].

The essential nutrient minerals for humans, listed in order by weight needed to be at the [[Dietary Reference Intake|Recommended Dietary Allowance]] or [[Adequate Intake]] are [[potassium]], [[chlorine]], [[sodium]], [[calcium]], [[phosphorus]], [[magnesium]], [[iron]], [[zinc]], [[manganese]], [[copper]], [[iodine]], [[chromium]], [[molybdenum]], [[selenium]] and [[cobalt]] (the last as a component of vitamin B<sub>12</sub>). 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]]. Essential and purportedly essential minerals are marketed as dietary supplements, individually and in combination with vitamins and other minerals.

Although as a general rule, dietary supplement labeling and marketing are not allowed to make disease prevention or treatment claims, the U.S. FDA has for some foods and dietary supplements reviewed the science, concluded that there is significant scientific agreement, and published specifically worded allowed health claims. An initial ruling allowing a health claim for calcium dietary supplements and [[osteoporosis]] was later amended to include calcium supplements with or without vitamin D, effective January 1, 2010. Examples of allowed wording are shown below. In order to qualify for the calcium health claim, a dietary supplement must contain at least 20% of the Reference Dietary Intake, which for calcium means at least 260&nbsp;mg/serving.<ref>{{cite web | url = https://www.regulations.gov/document?D=FDA-2004-P-0205-0006 | title = Food Labeling: Health Claims; Calcium and Osteoporosis, and Calcium, Vitamin D, and Osteoporosis | publisher = U.S. Food and Drug Administration | date = 29 September 2008 }}</ref>

* "Adequate calcium throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis."
* "Adequate calcium as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life."
* "Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis."
* "Adequate calcium and vitamin D as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life."

In the same year, the European Food Safety Authority also approved a dietary supplement health claim for calcium and vitamin D and the reduction of the risk of osteoporotic fractures by reducing bone loss.<ref>{{cite journal|doi=10.2903/j.efsa.2010.1609 | volume=8 | title=Scientific Opinion in relation to the authorisation procedure for health claims on calcium and vitamin D and the reduction of the risk of osteoporotic fractures by reducing bone loss pursuant to Article 14 of Regulation (EC) No 1924/2006 | year=2010 | journal=EFSA Journal | issue=5 | page=1609| doi-access=free }}</ref>
The U.S. FDA also approved Qualified Health Claims (QHCs) for various health conditions for calcium, selenium and [[Chromium(III) picolinate|chromium picolinate]].<ref name=FDA-QHC>{{cite web | url = https://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm072756.htm | archive-url = https://web.archive.org/web/20131126045549/https://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm072756.htm | archive-date = 26 November 2013 | title = Qualified Health Claims: Letters of Enforcement Discretion | publisher = U.S. Food and Drug Administration | date = }}</ref> QHCs are supported by scientific evidence, but do not meet the more rigorous "significant scientific agreement" standard required for an authorized health claim. If dietary supplement companies choose to make such a claim then the FDA stipulates the exact wording of the QHC to be used on labels and in marketing materials. The wording can be onerous: "One study suggests that selenium intake may reduce the risk of [[bladder cancer]] in women. However, one smaller study showed no reduction in risk. Based on these studies, FDA concludes that it is highly uncertain that selenium supplements reduce the risk of bladder cancer in women."<ref>{{cite web | url = https://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm168527.htm | archive-url = https://wayback.archive-it.org/7993/20171114183712/https://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm168527.htm | url-status = dead | archive-date = 2017-11-14 | title = Selenium and a Reduced Risk of Site-specific Cancers | id = FDA-2008-Q-0323 | publisher = U.S. Food and Drug Administration | date = 19 June 2009 }}</ref>

===Proteins and amino acids===
{{main|Protein (nutrient)|Amino acid}}

Protein-containing supplements, either ready-to-drink or as powders to be mixed into water, are marketed as aids to people recovering from illness or injury, those hoping to thwart the [[sarcopenia]] of old age,<ref>{{cite journal | vauthors = Liao CD, Tsauo JY, Wu YT, Cheng CP, Chen HC, Huang YC, Chen HC, Liou TH | display-authors = 6 | title = Effects of protein supplementation combined with resistance exercise on body composition and physical function in older adults: a systematic review and meta-analysis | journal = The American Journal of Clinical Nutrition | volume = 106 | issue = 4 | pages = 1078–91 | date=October 2017 | pmid = 28814401 | doi = 10.3945/ajcn.116.143594 | doi-access = free }}</ref><ref name=Colonetti2017 /> to athletes who believe that strenuous physical activity increases protein requirements,<ref name=IOC/> to people hoping to lose weight while minimizing muscle loss, i.e., conducting a [[protein-sparing modified fast]],<ref>{{cite journal | vauthors = Stonehouse W, Wycherley T, Luscombe-Marsh N, Taylor P, Brinkworth G, Riley M | title = Dairy Intake Enhances Body Weight and Composition Changes during Energy Restriction in 18–50-Year-Old Adults-A Meta-Analysis of Randomized Controlled Trials | journal = Nutrients | volume = 8 | issue = 7 | page = 394 | date = July 2016 | pmid = 27376321 | pmc = 4963870 | doi = 10.3390/nu8070394 | doi-access = free }}</ref> and to people who want to increase muscle size for performance and appearance. [[Whey protein]] is a popular ingredient,<ref name=Colonetti2017>{{cite journal | vauthors = Colonetti T, Grande AJ, Milton K, Foster C, Alexandre MC, Uggioni ML, Rosa MI | title = Effects of whey protein supplement in the elderly submitted to resistance training: systematic review and meta-analysis | journal = International Journal of Food Sciences and Nutrition | volume = 68 | issue = 3 | pages = 257–64 | date = May 2017 | pmid = 27653283 | doi = 10.1080/09637486.2016.1232702 | s2cid = 205659209 | url = https://ueaeprints.uea.ac.uk/id/eprint/66111/1/Accepted_manuscript.pdf }}</ref><ref>{{cite journal | vauthors = Naclerio F, Larumbe-Zabala E | title = Effects of Whey Protein Alone or as Part of a Multi-ingredient Formulation on Strength, Fat-Free Mass, or Lean Body Mass in Resistance-Trained Individuals: A Meta-analysis | journal = Sports Medicine | volume = 46 | issue = 1 | pages = 125–37 | date = January 2016 | pmid = 26403469 | doi = 10.1007/s40279-015-0403-y | s2cid = 31140351 | url = http://gala.gre.ac.uk/id/eprint/15355/2/15355_Naclerio_Effects%20of%20whey%20protein%20%28AAM%29%202016.pdf }}</ref><ref name=Miller2014>{{cite journal | vauthors = Miller PE, Alexander DD, Perez V | title = Effects of whey protein and resistance exercise on body composition: a meta-analysis of randomized controlled trials | journal = Journal of the American College of Nutrition | volume = 33 | issue = 2 | pages = 163–75 | year = 2014 | pmid = 24724774 | doi = 10.1080/07315724.2013.875365 | s2cid = 19434136 }}</ref> but products may also incorporate [[casein]], [[Soy protein|soy]], [[Pea protein|pea]], [[Hemp protein|hemp]] or [[rice protein]]. A meta-analysis found a moderate degree of evidence in favor of whey protein supplements use as a safe and effective adjunct to an athlete's training and recovery, including benefits for [[endurance]], average power, [[muscle mass]], and reduced perceived [[exercise intensity]].<ref name="Lam_2019">{{cite journal | vauthors = Lam FC, Bukhsh A, Rehman H, Waqas MK, Shahid N, Khaliel AM, Elhanish A, Karoud M, Telb A, Khan TM | display-authors = 6 | title = Efficacy and Safety of Whey Protein Supplements on Vital Sign and Physical Performance Among Athletes: A Network Meta-Analysis | journal = Frontiers in Pharmacology | volume = 10 | page = 317 | date = April 2019 | pmid = 31068804 | pmc = 6491698 | doi = 10.3389/fphar.2019.00317 | doi-access = free }}</ref>

According to US and Canadian [[Dietary Reference Intake]] guidelines, the protein [[Recommended Dietary Allowance]] (RDA) for adults is based on 0.8 grams protein per kilogram body weight. The recommendation is for sedentary and lightly active people.<ref name="DRIProteinChpt">{{cite book | title = Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids| publisher = Institute of Medicine. National Academy Press| year = 2005| url = https://archive.org/details/isbn_9780309085250| doi = 10.17226/10490| isbn = 978-0-309-08525-0| url-access = registration}}</ref><ref name="IJSNEM">{{cite journal | vauthors = Bilsborough S, Mann N | title = A review of issues of dietary protein intake in humans | journal = International Journal of Sport Nutrition and Exercise Metabolism | volume = 16 | issue = 2 | pages = 129–52 | date = April 2006 | pmid = 16779921 | doi = 10.1123/ijsnem.16.2.129 | s2cid = 10339366 | doi-access = free }}</ref><ref name=tarnopolsky>{{cite journal | vauthors = Tarnopolsky MA, Atkinson SA, MacDougall JD, Chesley A, Phillips S, Schwarcz HP | title = Evaluation of protein requirements for trained strength athletes | journal = Journal of Applied Physiology | volume = 73 | issue = 5 | pages = 1986–95 | date = November 1992 | pmid = 1474076 | doi = 10.1152/jappl.1992.73.5.1986 | s2cid = 46188182 }}</ref> Scientific reviews can conclude that a high protein diet, when combined with exercise, will increase muscle mass and strength,<ref name=lemon>{{cite journal |last1=Lemon|first1=PW | title=Do athletes need more dietary protein and amino acids? | journal = International Journal of Sport Nutrition | volume = 5 | issue = Suppl | pages = S39–61 | date = June 1995 | pmid = 7550257 | doi = 10.1123/ijsn.5.s1.s39 | s2cid = 27679614 }}</ref><ref name=Morton2017>{{cite journal | vauthors = Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM | display-authors = 6 | title = A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults | journal = British Journal of Sports Medicine | volume = 52 | issue = 6 | pages = 376–84 | date = March 2018 | pmid = 28698222 | pmc = 5867436 | doi = 10.1136/bjsports-2017-097608 }}</ref><!-- defined by transclusion from Bodybuilding supplement --><ref>{{cite journal | vauthors = Cermak NM, Res PT, de Groot LC, Saris WH, van Loon LJ | title = Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysis | journal = The American Journal of Clinical Nutrition | volume = 96 | issue = 6 | pages = 1454–64 | date = December 2012 | pmid = 23134885 | doi = 10.3945/ajcn.112.037556 | doi-access = free }}</ref> or conclude the opposite.<ref>{{cite journal | vauthors = Finger D, Goltz FR, Umpierre D, Meyer E, Rosa LH, Schneider CD | title = Effects of protein supplementation in older adults undergoing resistance training: a systematic review and meta-analysis | journal = Sports Medicine | volume = 45 | issue = 2 | pages = 245–55 | date = February 2015 | pmid = 25355074 | doi = 10.1007/s40279-014-0269-4 | s2cid = 31362761 }}</ref> The International Olympic Committee recommends protein intake targets for both strength and endurance athletes at about 1.2–1.8 g/kg body mass per day.<ref name=IOC>{{cite web | url = https://hub.olympic.org/athlete365/wp-content/uploads/2016/01/1378_IOC_NutritionAthleteHandbook_1e.pdf | title = Nutrition for Athletes | work = International Olympic Committee | archive-url = https://web.archive.org/web/20180122235001/https://hub.olympic.org/athlete365/wp-content/uploads/2016/01/1378_IOC_NutritionAthleteHandbook_1e.pdf | archive-date = 2018-01-22 | author = Nutrition Working Group of the Medical and Scientific Commission of the International Olympic Committee | date = June 2016}}</ref> One review proposed a maximum daily protein intake of approximately 25% of energy requirements, i.e., approximately 2.0 to 2.5 g/kg.<ref name="IJSNEM"/>

The same protein ingredients marketed as dietary supplements can be incorporated into [[meal replacement]] and [[medical food]] products, but those are regulated and labeled differently from supplements. In the United States, "meal replacement" products are foods and are labeled as such. These typically contain protein, carbohydrates, fats, vitamins and minerals. There may be content claims such as "good source of protein", "low fat" or "lactose free".<ref>{{cite web|url=http://www.foodprocessing.com/articles/2004/53.html|title=Regulatory Issues: Meal Replacements – Convenience or Compromise?|publisher=Food Processing|access-date=2018-01-22|archive-date=2013-08-15|archive-url=https://web.archive.org/web/20130815230155/http://www.foodprocessing.com/articles/2004/53.html|url-status=dead}}</ref> Medical foods, also nutritionally complete, are designed to be used while a person is under the care of a physician or other licensed healthcare professional.<ref>{{cite web | url = https://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/MedicalFoods/default.htm | title = Medical Foods Guidance Documents & Regulatory Information | date = 6 December 2017 | publisher = U.S. Food and Drug Administration. }}</ref><ref name = "FDA_FAQ_2016" /> Liquid medical food products – for example, [[Ensure]] – are available in regular and high protein versions.

Proteins are chains of [[amino acid]]s. Nine of these proteinogenic amino acids are considered essential for humans because they cannot be produced from other compounds by the human body and so must be taken in as food. Recommended intakes, expressed as milligrams per kilogram of body weight per day, have been established.<ref name="DRIProteinChpt"/> Other amino acids may be conditionally essential for certain ages or medical conditions. Amino acids, individually and in combinations, are sold as dietary supplements. The claim for supplementing with the [[branched-chain amino acid]]s leucine, valine and isoleucine is for stimulating muscle protein synthesis. A review of the literature concluded this claim was unwarranted.<ref>{{cite journal | vauthors = Charles EJ, Johnston LE, Herbert MA, Mehaffey JH, Yount KW, Likosky DS, Theurer PF, Fonner CE, Rich JB, Speir AM, Ailawadi G, Prager RL, Kron IL | display-authors = 6 | title = Impact of Medicaid Expansion on Cardiac Surgery Volume and Outcomes | journal = The Annals of Thoracic Surgery | volume = 104 | issue = 4 | pages = 1251–58 | date = October 2017 | pmid = 28552372 | pmc = 5610068 | doi = 10.1016/j.athoracsur.2017.03.079 }}</ref> In elderly people, supplementation with just [[leucine]] resulted in a modest (0.99&nbsp;kg) increase in lean body mass.<ref>{{cite journal | vauthors = Komar B, Schwingshackl L, Hoffmann G | title = Effects of leucine-rich protein supplements on anthropometric parameter and muscle strength in the elderly: a systematic review and meta-analysis | journal = The Journal of Nutrition, Health & Aging | volume = 19 | issue = 4 | pages = 437–46 | date = April 2015 | pmid = 25809808 | doi = 10.1007/s12603-014-0559-4 | s2cid = 24759289 | doi-access = free }}</ref> The non-essential amino acid [[arginine]], consumed in sufficient amounts, is thought to act as a donor for the synthesis of nitric oxide, a vasodilator. A review confirmed blood pressure lowering.<ref>{{cite journal | vauthors = Dong JY, Qin LQ, Zhang Z, Zhao Y, Wang J, Arigoni F, Zhang W | title = Effect of oral L-arginine supplementation on blood pressure: a meta-analysis of randomized, double-blind, placebo-controlled trials | journal = American Heart Journal | volume = 162 | issue = 6 | pages = 959–65 | date = December 2011 | pmid = 22137067 | doi = 10.1016/j.ahj.2011.09.012 }}</ref> [[Taurine]], a popular dietary supplement ingredient with claims made for sports performance, is technically not an amino acid. It is synthesized in the body from the amino acid [[cysteine]].<ref>{{cite web|url=http://www.dictionary.com/browse/amino-acid|title=the definition of amino acid|website=Dictionary.com|access-date=2017-02-22}}</ref>

===Bodybuilding supplements===
{{Excerpt|Bodybuilding supplement}}

===Beauty supplements===
Beauty supplements, particularly those aimed at improving the health of skin, hair, and nails, are commonly marketed within the wellness and supplement markets. These products typically include ingredients, such as [[collagen]], which is reputed to improve the appearance and condition of skin, hair, and nails.{{medcn|date=April 2025}} Other typical ingredients include [[biotin]], [[keratin]], and [[omega-3 fatty acid]]s, which are promoted for their alleged benefits to skin and hair health. Demand for these beauty supplements has risen markedly in the [[21st century]].{{cn|date=April 2025}} Despite the apparent rise in demand, scientific evidence supporting the efficacy of ingredients like biotin for the purpose of hair growth remains unproven.<ref name="lpi-biotin">{{cite web |title=Biotin |url=https://lpi.oregonstate.edu/mic/vitamins/biotin |publisher=Micronutrient Information Center, Linus Pauling Institute, Oregon State University |access-date=9 April 2025 |date=March 2023}}</ref>

===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>

===Natural products===
{{Main|Natural product}}
{{See also|Phytochemical|Herbalism|Traditional Chinese medicine}}
[[File:Springtime St. John's Wort (12610079565).jpg|thumb|St. John's wort petals used in natural product supplements]]

Dietary supplements can be manufactured using intact sources or [[extract]]s from plants, animals, algae, fungi or lichens, including such examples as [[ginkgo biloba]], [[curcumin]], [[cranberry]], [[St. John's wort]], [[ginseng]], [[resveratrol]], [[glucosamine]] and [[collagen]].<ref name="efsa18">{{cite web|title=Botanicals|url=https://www.efsa.europa.eu/en/topics/topic/botanicals|publisher=European Food Safety Authority|access-date=1 February 2018|date=2018}}</ref><ref name="prince">{{cite web| vauthors = Prince J |title=U.S. Herbal Supplement Sales Up 7.7% in 2016|url=http://www.nutritionaloutlook.com/herbs-botanicals/us-herbal-supplement-sales-77-2016|publisher=Nutritional Outlook|access-date=1 February 2018|date=13 September 2017}}</ref><ref name="canada">{{cite web|title=Natural and Non-prescription Health Products|url=https://www.canada.ca/en/health-canada/services/drugs-health-products/natural-non-prescription.html|publisher=Government of Canada|access-date=1 February 2018|date=2018}}</ref> Products bearing promotional claims of health benefits are sold without requiring a prescription in [[pharmacy|pharmacies]], [[supermarket]]s, specialist shops, military [[commissary|commissaries]], [[buyers club]]s, [[direct selling]] organizations, and the internet.<ref name=prince/> While most of these products have a long history of use in [[herbalism]] and various forms of traditional medicine, concerns exist about their actual efficacy, safety and consistency of quality.<ref name="quackwatch">{{cite web|url=https://www.quackwatch.com/01QuackeryRelatedTopics/herbs.html|title=The herbal minefield|vauthors=Barrett S|publisher=Quackwatch|date=23 November 2013|access-date=1 February 2018|archive-date=18 August 2018|archive-url=https://web.archive.org/web/20180818071259/http://quackwatch.com/01QuackeryRelatedTopics/herbs.html|url-status=dead}}</ref><ref name="zhang">{{cite journal | vauthors = Zhang J, Wider B, Shang H, Li X, Ernst E | title = Quality of herbal medicines: challenges and solutions | journal = Complementary Therapies in Medicine | volume = 20 | issue = 1–2 | pages = 100–06 | year = 2012 | pmid = 22305255 | doi = 10.1016/j.ctim.2011.09.004 }}</ref><ref name="coghlan">{{cite journal | vauthors = Coghlan ML, Haile J, Houston J, Murray DC, White NE, Moolhuijzen P, Bellgard MI, Bunce M | display-authors = 6 | title = Deep sequencing of plant and animal DNA contained within traditional Chinese medicines reveals legality issues and health safety concerns | journal = PLOS Genetics | volume = 8 | issue = 4 | page = e1002657 | year = 2012 | pmid = 22511890 | pmc = 3325194 | doi = 10.1371/journal.pgen.1002657 | doi-access = free }}</ref> Canada has published a manufacturer and consumer guide describing quality, licensing, standards, identities, and common contaminants of natural products.<ref name="canada-guide">{{cite web|title=Quality of Natural Health Products Guide|url=https://www.canada.ca/en/health-canada/services/drugs-health-products/natural-non-prescription/legislation-guidelines/guidance-documents/quality-guide.html|publisher=Government of Canada|access-date=1 February 2018|date=1 May 2015}}</ref>

In 2019, sales of herbal supplements just in the United States alone were $9.6 billion, with the market growing at approximately 8.6% per year,<ref>{{cite web|title=US Sales of Herbal Supplements Increase by 8.6% in 2019 –American Botanical Council|url=https://www.herbalgram.org/resources/herbalgram/issues/127/table-of-contents/herbalgram-127-herb-market-report-american-botanical-council/|access-date=2021-07-30|website=www.herbalgram.org}}</ref> with [[cannabidiol]] and mushroom product sales as the highest.<ref name="nw">{{cite web |title=Herbal Supplements Post Strongest Sales Growth in Two Decades |url=https://www.nutraceuticalsworld.com/contents/view_breaking-news/2019-09-23/herbal-supplements-post-strongest-sales-growth-in-two-decades |publisher=Nutraceuticals World |access-date=25 September 2019 |date=23 September 2019}}</ref> Italy, Germany, and [[Eastern Europe]]an countries were leading consumers of botanical supplements in 2016, with [[European Union]] market growth forecast to be $8.7 billion by 2020.<ref name="becker">{{cite web| vauthors = Becker M |title=Dietary Supplements in Europe Poised for Profound Growth|url=https://www.naturalproductsinsider.com/blogs/supplement-perspectives/2016/03/dietary-supplements-in-europe-poised-for-profound.aspx|publisher=Natural Products Insider|access-date=1 February 2018|date=8 March 2016}}</ref>

===Probiotics===
{{Main|Probiotic}}
Claimed benefits of using [[probiotic]] supplements are not supported by sufficient clinical evidence.<ref>{{cite web|title=Probiotic Health Claims|url=https://www.fsai.ie/faq/probiotic_health_claims.html|publisher=Food Safety Authority of Ireland|access-date=4 February 2018|date=5 May 2017|archive-date=10 July 2017|archive-url=https://web.archive.org/web/20170710214129/https://www.fsai.ie/faq/probiotic_health_claims.html|url-status=dead}}</ref><ref>{{cite journal | vauthors = Rijkers GT, de Vos WM, Brummer RJ, Morelli L, Corthier G, Marteau P | title = Health benefits and health claims of probiotics: bridging science and marketing | journal = The British Journal of Nutrition | volume = 106 | issue = 9 | pages = 1291–96 | date = November 2011 | pmid = 21861940 | doi = 10.1017/S000711451100287X | doi-access = free }}</ref><ref>{{cite journal | vauthors = Slashinski MJ, McCurdy SA, Achenbaum LS, Whitney SN, McGuire AL | title = 'Snake-oil,' 'quack medicine,' and 'industrially cultured organisms:' biovalue and the commercialization of human microbiome research | journal = BMC Medical Ethics | volume = 13 | page=28 | date=October 2012 | pmid = 23110633 | pmc = 3512494 | doi = 10.1186/1472-6939-13-28 | doi-access = free }}</ref> Meta-analysis studies have reported a modest reduction of antibiotic-associated diarrhea and acute diarrhea in children taking probiotics.<ref>{{cite journal | vauthors = Guo Q, Goldenberg JZ, Humphrey C, El Dib R, Johnston BC | title = Probiotics for the prevention of pediatric antibiotic-associated diarrhea | journal = The Cochrane Database of Systematic Reviews | volume = 4 | page = CD004827 | date = April 2019 | issue = 4 | pmid = 31039287 | pmc = 6490796 | doi = 10.1002/14651858.CD004827.pub5 | collaboration = Cochrane IBD Group }}</ref> There is limited evidence in support of adults using mono-strain and multi-strain containing probiotics for the alleviation of symptoms associated with [[irritable bowel syndrome]].<ref>{{Cite journal|last1=Dale|first1=HF|last2=Rasmussen|first2=SH|last3=Asiller|first3=ÖÖ|last4=Lied|first4=GA |date=September 2019|title=Probiotics in Irritable Bowel Syndrome: An Up-to-Date Systematic Review|journal=Nutrients|volume=11|issue=9|page=2048|doi=10.3390/nu11092048|pmid=31480656|issn=2072-6643|pmc=6769995|doi-access=free}}</ref> Probiotic supplements are generally regarded as safe.<ref>{{cite journal | vauthors=Doron S, Snydman DR | title=Risk and safety of probiotics | journal=Clinical Infectious Diseases | volume=60 | issue=Suppl 2 | pages=S129–34 | date=May 2015 | pmid=25922398 | pmc=4490230 | doi=10.1093/cid/civ085}}</ref>

=== Fertility ===
{{Main|Fertility}}
A meta-analysis provided preliminary evidence that men treated with supplements containing [[selenium in biology|selenium]], [[zinc]], [[omega-3 fatty acid]]s, [[coenzyme Q10|coenzyme Q<sub>10</sub>]] or [[carnitine]]s reported improvements in total sperm count, concentration, motility, and morphology.<ref>{{cite journal | vauthors = Salas-Huetos A, Rosique-Esteban N, Becerra-Tomás N, Vizmanos B, Bulló M, Salas-Salvadó J | title = The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters: A Systematic Review and Meta-Analysis of Randomized Clinical Trials | journal = Advances in Nutrition | volume = 9 | issue = 6 | pages = 833–48 | date = November 2018 | pmid = 30462179 | doi = 10.1093/advances/nmy057 | pmc = 6247182 }}</ref> A review concluded that omega-3 taken through supplements and diet might improve semen quality in infertile men.<ref>{{cite journal | vauthors = Falsig AL, Gleerup CS, Knudsen UB | title = The influence of omega-3 fatty acids on semen quality markers: a systematic PRISMA review | journal = Andrology | volume = 7 | issue = 6 | pages = 794–803 | date = November 2019 | pmid = 31116515 | doi = 10.1111/andr.12649 | doi-access = free }}</ref> A 2021 review also supported selenium, zinc, omega-3 fatty acids, coenzyme Q<sub>10</sub> or carnitines, but warned that "excessive use of antioxidants may be detrimental to the spermatic function and many of the over-the-counter supplements are not scientifically proven to improve fertility."<ref>{{cite journal | vauthors = Torres-Arce E, Vizmanos B, Babio N, Márquez-Sandoval F, Salas-Huetos A | title = Dietary Antioxidants in the Treatment of Male Infertility: Counteracting Oxidative Stress | journal = Biology | volume = 10 | issue = 3 | page = 241 | date = March 2021 | pmid = 33804600 | pmc = 8003818 | doi = 10.3390/biology10030241 | doi-access = free }}</ref>

There is low quality and insufficient evidence for the use of oral antioxidant supplements as a viable treatment for [[subfertile]] woman.<ref>{{cite journal | vauthors = Showell MG, Mackenzie-Proctor R, Jordan V, Hart RJ | title = Antioxidants for female subfertility | journal = The Cochrane Database of Systematic Reviews | volume = 8 | page = CD007807 | date = August 2020 | issue = 11 | pmid = 32851663 | doi = 10.1002/14651858.CD007807.pub4 | collaboration = Cochrane Gynaecology and Fertility Group | pmc = 8094745 }}</ref> A review provided evidence that taking [[Dehydroepiandrosterone (dietary supplement)|dehydroepiandrosterone]] before starting an ''in vitro'' fertilization series may increase pregnancy rates and decrease miscarriage likelihood.<ref>{{cite journal | vauthors = Schwarze JE, Canales J, Crosby J, Ortega-Hrepich C, Villa S, Pommer R | title = DHEA use to improve likelihood of IVF/ICSI success in patients with diminished ovarian reserve: A systematic review and meta-analysis | journal = JBRA Assisted Reproduction | volume = 22 | issue = 4 | pages = 369–74 | date = November 2018 | pmid = 30125071 | pmc = 6210617 | doi = 10.5935/1518-0557.20180046 }}</ref>

=== Prenatal ===
{{Main|Prenatal vitamins}}
[[Prenatal vitamins]] are dietary supplements commonly given to pregnant women to supply nutrients that may reduce health complications for the mother and [[fetus]]. Although prenatal vitamins are not meant to substitute for dietary nutrition, prenatal supplementation may be beneficial for pregnant women at risk of nutrient deficiencies because of diet limitations or restrictions. The most common components in prenatal vitamins include vitamins [[Vitamin B6|B<sub>6</sub>]], [[folate]], [[Vitamin B12|B<sub>12</sub>]], [[Vitamin C|C]], [[Vitamin D|D]], [[Vitamin E|E]], [[Iron supplement|iron]] and [[calcium]].<ref name="Brown_2020">{{cite journal | vauthors = Brown B, Wright C | title = Safety and efficacy of supplements in pregnancy | journal = Nutrition Reviews | volume = 78 | issue = 10 | pages = 813–26 | date = October 2020 | pmid = 31925443 | pmc = 7558284 | doi = 10.1093/nutrit/nuz101 }}</ref>

Sufficient intake of vitamin B<sub>6</sub> can lower the risk of early pregnancy loss and relieve symptoms of [[morning sickness]].<ref name="deregil">{{cite journal | vauthors = De-Regil LM, Peña-Rosas JP, Fernández-Gaxiola AC, Rayco-Solon P | title = Effects and safety of periconceptional oral folate supplementation for preventing birth defects | journal = The Cochrane Database of Systematic Reviews | issue = 12 | page = CD007950 | date = December 2015 | volume = 2015 | pmid = 26662928 | doi = 10.1002/14651858.CD007950.pub3 | pmc = 8783750 | collaboration = Cochrane Pregnancy and Childbirth Group }}</ref><ref>{{cite journal | vauthors = Matthews A, Haas DM, O'Mathúna DP, Dowswell T | title = Interventions for nausea and vomiting in early pregnancy | journal = The Cochrane Database of Systematic Reviews | volume = 2015 | issue = 9 | page = CD007575 | date = September 2015 | pmid = 26348534 | pmc = 7196889 | doi = 10.1002/14651858.CD007575.pub4 | collaboration = Cochrane Pregnancy and Childbirth Group }}</ref> Folate is also an essential nutrient for pregnant women to prevent [[neural tube defect]]s.<ref name=deregil/> In 2006, the World Health Organization endorsed the recommendation for women of child-bearing age to consume 400 [[microgram]]s of folate through the diet daily if planning a pregnancy.<ref>{{cite journal | vauthors = McStay CL, Prescott SL, Bower C, Palmer DJ | title = Maternal Folic Acid Supplementation during Pregnancy and Childhood Allergic Disease Outcomes: A Question of Timing? | journal = Nutrients | volume = 9 | issue = 2 | page = 123 | date = February 2017 | pmid = 28208798 | pmc = 5331554 | doi = 10.3390/nu9020123 | doi-access = free }}</ref> A 2013 review found folic acid supplementation during pregnancy did not affect the mother's health other than a risk reduction on low pre-delivery serum folate and megaloblastic anemia.<ref>{{cite journal | vauthors = Lassi ZS, Salam RA, Haider BA, Bhutta ZA | title = Folic acid supplementation during pregnancy for maternal health and pregnancy outcomes | journal = The Cochrane Database of Systematic Reviews | issue = 3 | page = CD006896 | date = March 2013 | volume = 2013 | pmid = 23543547 | doi = 10.1002/14651858.cd006896.pub2 | pmc = 10069458 }}</ref> There is little evidence to suggest that vitamin D supplementation improves prenatal outcomes in hypertensive disorders and [[gestational diabetes]].<ref name="pmid31581312">{{cite journal | vauthors = Palacios C, Trak-Fellermeier MA, Martinez RX, Lopez-Perez L, Lips P, Salisi JA, John JC, Peña-Rosas JP | display-authors = 6 | title = Regimens of vitamin D supplementation for women during pregnancy | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | issue = 10| page = CD013446 | date = October 2019 | pmid = 31581312 | pmc = 6776191 | doi = 10.1002/14651858.CD013446 | url = }}</ref><ref>{{cite web|title=Vitamin D supplementation during pregnancy |url=http://www.who.int/elena/titles/vitamind_supp_pregnancy/en/|archive-url=https://web.archive.org/web/20140330091855/http://www.who.int/elena/titles/vitamind_supp_pregnancy/en/|url-status=dead|archive-date=March 30, 2014|access-date=2021-07-30|website=WHO}}</ref> Evidence does not support the routine use of vitamin E supplementation during pregnancy to prevent adverse events, such as preterm birth, fetal or neonatal death, or maternal hypertensive disorders.<ref>{{cite journal | vauthors = Rumbold A, Ota E, Hori H, Miyazaki C, Crowther CA | title = Vitamin E supplementation in pregnancy | journal = The Cochrane Database of Systematic Reviews | issue = 9 | page = CD004069 | date = September 2015 | volume = 2016 | pmid = 26343254 | doi = 10.1002/14651858.CD004069.pub3 | pmc = 8406700 }}</ref><ref>{{cite web|title= Vitamin E supplementation in pregnancy|url=http://www.who.int/elena/titles/review_summaries/vitaminE-pregnancy/en/|archive-url=https://web.archive.org/web/20210730225711/https://www.who.int/elena/titles/review_summaries/vitaminE-pregnancy/en/|url-status=dead|archive-date=July 30, 2021|access-date=2021-07-30|website=WHO}}</ref>

Iron supplementation can lower the risk of [[Iron-deficiency anemia|iron deficiency anemia]] for pregnant women.<ref>{{Cite journal |last1=Finkelstein |first1=Julia L. |last2=Cuthbert |first2=Anna |last3=Weeks |first3=Jo |last4=Venkatramanan |first4=Sudha |last5=Larvie |first5=Doreen Y. |last6=De-Regil |first6=Luz Maria |last7=Garcia-Casal |first7=Maria Nieves |date=2024-08-15 |title=Daily oral iron supplementation during pregnancy |journal=The Cochrane Database of Systematic Reviews |volume=2024 |issue=8 |pages=CD004736 |doi=10.1002/14651858.CD004736.pub6 |issn=1469-493X |pmc=11325660 |pmid=39145520|pmc-embargo-date=August 15, 2025 }}</ref> In 2020, the World Health Organization updated recommendations for adequate calcium levels during pregnancy to prevent [[Hypertensive disease of pregnancy|hypertensive disorders]].<ref>{{cite journal | vauthors = Hofmeyr GJ, Manyame S, Medley N, Williams MJ | title = Calcium supplementation commencing before or early in pregnancy, for preventing hypertensive disorders of pregnancy | journal = The Cochrane Database of Systematic Reviews | volume = 2019 | page = CD011192 | date = September 2019 | issue = 9 | pmid = 31523806 | pmc = 6745517 | doi = 10.1002/14651858.CD011192.pub3 | collaboration = Cochrane Pregnancy and Childbirth Group }}</ref><ref>{{cite web|title= Calcium supplementation during pregnancy to reduce the risk of pre-eclampsia |url=http://www.who.int/elena/titles/guidance_summaries/calcium_pregnancy/en/|archive-url=https://web.archive.org/web/20150102183304/http://www.who.int/elena/titles/guidance_summaries/calcium_pregnancy/en/|url-status=dead|archive-date=January 2, 2015|access-date=2021-07-30|website=WHO}}</ref>

=== Pharmacotherapy ===
Individuals with [[hypokalemic sensory overstimulation]] are sometimes diagnosed as having attention deficit hyperactivity disorder (ADHD), raising the possibility that a subtype of ADHD has a cause that can be understood mechanistically and treated in a novel way. The sensory overload is treatable with oral [[potassium gluconate]].