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{{short description|Nutrients required by organisms in small amounts}}
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{{Infobox drug class
| Name                = Vitamin
| Image               = B vitamin supplement tablets.jpg
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| Caption             = A bottle of B-complex vitamin pills
| Pronounce         = {{IPAc-en|uk|ˈ|v|ɪ|t|ə|m|ɪ|n|,_|ˈ|v|aɪ|t|-}} {{respell|VIT|ə|min|,_|VYTE|-}},<br />{{IPAc-en|us|ˈ|v|aɪ|t|ə|m|ɪ|n}} {{respell|VY|tə|min}}<ref>{{cite EPD|18}}</ref>
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| Drugs.com           = <!-- {{Drugs.com|drug-class|?}} -->
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'''Vitamins''' are [[Organic compound|organic molecules]] (or a set of closely related molecules called [[vitamer|vitamers]]) that are essential to an [[organism]] in small quantities for proper [[metabolism|metabolic]] function. These [[Nutrient#Essential nutrients|essential nutrients]] cannot be [[biosynthesis|synthesized]] in the organism in sufficient quantities for survival, and therefore must be obtained through the [[Diet (nutrition)|diet]]. For example, [[vitamin C]] can be synthesized by some species but not by others; it is not considered a vitamin in the first instance but is in the second.  Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, there are eight vitamers of [[vitamin E]]: four [[tocopherol]]s and four [[tocotrienol]]s.

The term ''vitamin'' does not include the three other groups of [[essential nutrient]]s: [[mineral (nutrient)|minerals]], [[essential fatty acid]]s, and [[essential amino acid]]s.<ref>{{cite book | vauthors = Maton A, Hopkins J, McLaughlin CW, Johnson S, Warner MQ, LaHart D, Wright JD |title = Human Biology and Health |publisher = Prentice Hall |date = 1993 |location = Englewood Cliffs, NJ |isbn = 978-0-13-981176-0 |oclc = 32308337 |url-access = registration |url = https://archive.org/details/humanbiologyheal00scho }}</ref>

Major health organizations list thirteen vitamins:<ref>{{Cite web|title=Vitamins and Minerals|url=https://www.nia.nih.gov/health/vitamins-and-minerals|archive-url=https://web.archive.org/web/20170801165317/https://www.nia.nih.gov/health/vitamins-and-minerals|url-status=dead|archive-date=1 August 2017|website=National Institute on Aging|language=en|access-date=12 May 2020}}</ref><ref>{{Cite book|url=https://www.who.int/nutrition/publications/micronutrients/9241546123/en/|archive-url=https://web.archive.org/web/20121212005813/http://www.who.int/nutrition/publications/micronutrients/9241546123/en/|url-status=dead|archive-date=12 December 2012|title=Vitamin and mineral requirements in human nutrition 2nd Edition|publisher=World Health Organization and Food and Agriculture Organization of the United Nations|year=2004|isbn=9241546123|pages=340–341}}</ref><ref>{{CELEX|32006R1925|text=Regulation (EC) No 1925/2006 of the European Parliament and of the Council of 20 December 2006 on the addition of vitamins and minerals and of certain other substances to foods}}</ref>

* [[Vitamin A]] (all-''trans''-[[retinol]]s, all-''trans''-retinyl-esters, as well as all-''trans''-[[β-carotene]] and other [[provitamin]] A carotenoids)
* Vitamin B<sub>1</sub> ([[thiamine]])
* Vitamin B<sub>2</sub> ([[riboflavin]])
* Vitamin B<sub>3</sub> ([[niacin (substance)|niacin]])
* Vitamin B<sub>5</sub> ([[pantothenic acid]])
* Vitamin B<sub>6</sub> ([[pyridoxine]])
* Vitamin B<sub>7</sub> ([[biotin]])
* Vitamin B<sub>9</sub> ([[folic acid]] and [[folate]]s)
* Vitamin B<sub>12</sub> ([[cobalamin]]s)
* Vitamin C ([[ascorbic acid]] and [[ascorbate]]s)
* [[Vitamin D]] ([[calciferol]]s)
* [[Vitamin E]] ([[tocopherols]] and [[tocotrienols]])
* [[Vitamin K]] ([[phylloquinone]]s, [[menaquinone]]s, and [[menadione]]s) 

Some sources include a fourteenth, [[choline]].<ref>{{Cite web |title=Listing of vitamins |url=https://www.health.harvard.edu/staying-healthy/listing_of_vitamins | publisher = Harvard Health Publishing |date=9 June 2009|access-date=12 May 2020}}</ref>

Vitamins have diverse biochemical functions. Vitamin A acts as a regulator of cell and tissue growth and differentiation. Vitamin D provides a hormone-like function, regulating mineral metabolism for bones and other organs. The [[B complex]] vitamins function as enzyme [[cofactor (biochemistry)|cofactor]]s (coenzymes) or the [[precursor (chemistry)|precursors]] for them. Vitamins C and E function as [[antioxidant]]s.<ref name= Bender>{{Cite book | vauthors = Bender DA |title = Nutritional biochemistry of the vitamins|date = 2003|publisher = Cambridge University Press|location = Cambridge, UK|isbn = 978-0-521-80388-5}}</ref> Both deficient and excess intake of a vitamin can potentially cause clinically significant illness, although excess intake of water-soluble vitamins is less likely to do so.

All the vitamins were discovered between 1910 and 1948. Historically, when intake of vitamins from diet was lacking, the results were vitamin deficiency diseases. Then, starting in 1935, commercially produced tablets of yeast-extract vitamin B complex and semi-synthetic vitamin C became available.<ref name="Price" /> This was followed in the 1950s by the mass production and marketing of [[vitamin supplement]]s, including [[multivitamin]]s, to prevent vitamin deficiencies in the general population.<ref name="Price" /> Governments have mandated the addition of some vitamins to [[staple food]]s such as flour or milk, referred to as [[food fortification]], to prevent deficiencies.<ref name=FoodFortif>{{cite web |url=http://www.ffinetwork.org/why_fortify/index.html |title=Food Fortification Initiative |website=Food Fortification Initiative, Enhancing Grains for Better Lives |access-date=18 August 2018 |archive-date=4 April 2017 |archive-url=https://web.archive.org/web/20170404131451/http://www.ffinetwork.org/why_fortify/index.html |url-status=dead }}</ref> Recommendations for folic acid supplementation during [[Nutrition and pregnancy|pregnancy]] reduced risk of infant [[neural tube defect]]s.<ref name=Wilson2015>{{cite journal | vauthors = Wilson RD, Wilson RD, Audibert F, Brock JA, Carroll J, Cartier L, Gagnon A, Johnson JA, Langlois S, Murphy-Kaulbeck L, Okun N, Pastuck M, Deb-Rinker P, Dodds L, Leon JA, Lowel HL, Luo W, MacFarlane A, McMillan R, Moore A, Mundle W, O'Connor D, Ray J, Van den Hof M | display-authors = 6 | title = Pre-conception Folic Acid and Multivitamin Supplementation for the Primary and Secondary Prevention of Neural Tube Defects and Other Folic Acid-Sensitive Congenital Anomalies | journal = Journal of Obstetrics and Gynaecology Canada | volume = 37 | issue = 6 | pages = 534–552 | date = June 2015 | pmid = 26334606 | doi = 10.1016/s1701-2163(15)30230-9 | doi-access = free }}</ref>

==List of vitamins==
{| class="wikitable sortable col3center"
|-
! colspan="2" scope="col" | Vitamin
! class="unsortable" scope="col" | [[Vitamer]]s
! scope="col" | [[Solubility]]
! class="unsortable" scope="col" | U.S. [[Reference Daily Intake|recommended dietary allowances]]<br /> per day<br /> ages 19–70)<ref name=DRITable />
! class="unsortable" scope="col" | Deficiency disease(s)
! class="unsortable" scope="col" | Overdose syndrome/symptoms
! class="unsortable" scope="col" | Food sources
|-
! colspan="2" scope="row" | [[vitamin A|A]]
| {{Unbulleted list
  | all-''trans''-[[retinol]] ([[retinal]], [[retinoic acid]], [[retinoids]])
  | provitamin A [[carotenoid]]s ([[alpha-carotene]], [[beta-carotene]], [[gamma-carotene]])
  | [[xanthophyll]] beta-[[cryptoxanthin]]
  }}
| {{CellCategory |1 |fat |align=mc}}
| 900&nbsp;μg/700&nbsp;μg
| [[night blindness]], [[hyperkeratosis]], and [[keratomalacia]]<ref name="GOVa">{{cite web| url = http://dietary-supplements.info.nih.gov/factsheets/vitamina.asp| title = Vitamin A: Fact Sheet for Health Professionals| work = [[National Institute of Health]]: Office of Dietary Supplements| date = 5 June 2013| access-date = 3 August 2013| archive-date = 23 September 2009| archive-url = https://web.archive.org/web/20090923181436/http://dietary-supplements.info.nih.gov/factsheets/vitamina.asp| url-status = dead}}</ref>
| [[hypervitaminosis A]]
| from animal origin as vitamin A / all-''trans''-retinol: fish in general, liver and dairy products;

from plant origin as provitamin A / all-''trans''-beta-carotene: orange, ripe yellow fruits, leafy vegetables, carrots, pumpkin, squash, spinach
|-
! rowspan="8" | [[B vitamins|B]]
! scope="row" | [[vitamin B1|B<sub>1</sub>]]
| {{Unbulleted list
  | [[thiamine]]
  | [[thiamine monophosphate]]
  | [[thiamine pyrophosphate]]
  }}
| {{CellCategory |4 |water |align=mc}}
| 1.2&nbsp;mg/1.1&nbsp;mg
| [[beriberi]], [[Wernicke–Korsakoff syndrome]]
| drowsiness and muscle relaxation<ref>{{cite web |title = Thiamin, vitamin B1: MedlinePlus Supplements| url = https://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-thiamin.html| archive-url = https://web.archive.org/web/20060413090509/http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-thiamin.html| url-status = dead| archive-date = 13 April 2006|work=U.S. Department of Health and Human Services, National Institutes of Health }}</ref>
|pork, wholemeal grains, brown rice, vegetables, potatoes, liver, eggs
|-
! scope="row" | [[vitamin B2|B<sub>2</sub>]]
| {{Unbulleted list
  | [[riboflavin]]
  | [[flavin mononucleotide]] (FMN)
  | [[flavin adenine dinucleotide]] (FAD)
  }}
| {{CellCategory |4 |water |align=mc}}
| 1.3&nbsp;mg/1.1&nbsp;mg
| [[ariboflavinosis]], [[glossitis]], [[angular stomatitis]]
|
|dairy products, bananas, green beans, asparagus
|-
! scope="row" | [[vitamin B3|B<sub>3</sub>]]
| {{Unbulleted list
  | [[nicotinic acid]]
  | [[niacinamide]]
  | [[nicotinamide riboside]]
  }}
| {{CellCategory |4 |water |align=mc}}
| 16&nbsp;mg/14&nbsp;mg
| [[pellagra]]
| [[liver]] damage (doses > 2g/day)<ref>{{cite book|editor=Hardman, J.G.|title=Goodman and Gilman's Pharmacological Basis of Therapeutics|edition=10th|page=992|isbn=978-0071354691|date=2001|publisher=McGraw-Hill |display-editors=etal}}</ref> and [[niacin (nutrient)|other problems]]
|meat, fish, eggs, many vegetables, mushrooms, tree nuts
|-
! scope="row" | [[vitamin B5|B<sub>5</sub>]]
| {{Unbulleted list
  | [[pantothenic acid]]
  | [[panthenol]]
  | [[pantethine]]
  }}
| {{CellCategory |4 |water |align=mc}}
| 5&nbsp;mg/5&nbsp;mg

| [[paresthesia]]
| diarrhea; possibly nausea and heartburn.<ref>{{cite web |title = Pantothenic acid, dexpanthenol: MedlinePlus Supplements|url = https://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-vitaminb5.html|archive-url = https://web.archive.org/web/20060125124827/http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-vitaminb5.html|url-status = dead|archive-date = 25 January 2006|access-date = 5 October 2009|website=MedlinePlus}}</ref>
|meat, broccoli, avocados
|-
! [[vitamin B6|B<sub>6</sub>]]
| [[pyridoxine]], [[pyridoxamine]], [[pyridoxal]]
| {{CellCategory |4 |water |align=mc}}
| 1.3–1.7&nbsp;mg/1.2–1.5&nbsp;mg
| [[anemia]],<ref name="GOVb6">[http://dietary-supplements.info.nih.gov/factsheets/vitaminb6.asp Vitamin and Mineral Supplement Fact Sheets Vitamin B6] {{Webarchive|url=https://web.archive.org/web/20090923181520/http://dietary-supplements.info.nih.gov/factsheets/vitaminb6.asp |date=23 September 2009 }}. Dietary-supplements.info.nih.gov (15 September 2011). Retrieved on 3 August 2013.</ref> [[peripheral neuropathy]]
| impairment of [[proprioception]], nerve damage (doses > 100&nbsp;mg/day)<ref>{{cite book|chapter-url=https://www.nap.edu/read/6015/chapter/9#150|title=Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline|last1=Institute of Medicine|author-link=Institute of Medicine|publisher=The National Academies Press|year=1998|isbn=978-0-309-06554-2|location=Washington, DC|pages=150–195|chapter=Vitamin B<sub>6</sub>|doi=10.17226/6015|pmid=23193625|lccn=00028380|oclc=475527045}}</ref>
|meat, vegetables, tree nuts, bananas
|-
! [[biotin|B<sub>7</sub>]]
| [[biotin]]
| {{CellCategory |4 |water |align=mc}}
| AI: 30&nbsp;μg/30&nbsp;μg
| [[dermatitis]], [[enteritis]]
|
|raw egg yolk, liver, peanuts, leafy green vegetables
|-
! [[folate|B<sub>9</sub>]]
| [[folate]]s, [[folic acid]]
| {{CellCategory |4 |water |align=mc}}
| 400&nbsp;μg/400&nbsp;μg
| style="text-align:left;"| [[megaloblastic anemia]] and deficiency during pregnancy is associated with [[birth defects]] (e.g., [[neural tube|neural-tube]] defects)
| may mask symptoms of vitamin B<sub>12</sub> deficiency; [[folate#Toxicity|other effects]].
|leafy vegetables, pasta, bread, cereal, liver
|-
! [[vitamin B12|B<sub>12</sub>]]
| [[cyanocobalamin]], [[hydroxocobalamin]], [[methylcobalamin]], [[adenosylcobalamin]]
| {{CellCategory |4 |water |align=mc}}
| 2.4&nbsp;μg/2.4&nbsp;μg
| [[vitamin B12 deficiency anemia|vitamin B<sub>12</sub> deficiency anemia]]<ref name="GOVb12">[http://dietary-supplements.info.nih.gov/factsheets/vitaminb12.asp Vitamin and Mineral Supplement Fact Sheets Vitamin B12] {{Webarchive|url=https://web.archive.org/web/20090923181407/http://dietary-supplements.info.nih.gov/factsheets/vitaminb12.asp |date=23 September 2009 }}. Dietary-supplements.info.nih.gov (24 June 2011). Retrieved on 3 August 2013.</ref>
| none proven
|meat, poultry, fish, eggs, milk
|-
! colspan="2" |[[vitamin C|C]]
| [[ascorbic acid]]
| {{CellCategory |4 |water |align=mc}}
| 90&nbsp;mg/75&nbsp;mg
| [[scurvy]]
| stomach pain, diarrhoea, and flatulence.<ref name="NHS">[https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-c/ Vitamins and minerals] (3 March 2017). Retrieved on 2 June 2020.</ref>
|many fruits and vegetables, liver
|-
! rowspan="5" |[[vitamin D|D]]
! style="whitespace:nowrap;" |[[vitamin D1|D<sub>1</sub>]]
| mixture of molecular compounds of [[ergocalciferol]] with [[lumisterol]], 1:1
| {{CellCategory |1 |fat |align=mc}}
| rowspan="5" | 15&nbsp;μg/15&nbsp;μg
| rowspan="5" | [[rickets]] and [[osteomalacia]]
| rowspan="5" | [[hypervitaminosis D]]
|
|-
![[vitamin D2|D<sub>2</sub>]]
|[[ergocalciferol]]
| {{CellCategory |1 |fat |align=mc}}
|sunlight-exposed mushrooms and [[yeast]]
|-
![[vitamin D3|D<sub>3</sub>]]
|[[cholecalciferol]]
| {{CellCategory |1 |fat |align=mc}}
|fatty fish (mackerel, salmon, sardines), fish liver oils, eggs from hens fed vitamin D
|-
![[vitamin D4|D<sub>4</sub>]]
|[[22-dihydroergocalciferol]]
| {{CellCategory |1 |fat |align=mc}}
|
|-
![[vitamin D5|D<sub>5</sub>]]
|[[sitocalciferol]]
| {{CellCategory |1 |fat |align=mc}}
|
|-
! colspan="2" |[[vitamin E|E]]
| [[tocopherol]]s, [[tocotrienol]]s
| {{CellCategory |1 |fat |align=mc}}
| 15&nbsp;mg/15&nbsp;mg
| align="left" | deficiency is very rare; mild [[hemolytic anemia]] in newborn infants<ref name="Merck">[http://www.merck.com/mmhe/sec12/ch154/ch154a.html The Merck Manual: Nutritional Disorders: Vitamin Introduction] Please select specific vitamins from the list at the top of the page.</ref>
| possible increased incidence of congestive heart failure.<ref>{{cite news|url= https://www.highbeam.com/doc/1G1-132081136.html |archive-url= https://web.archive.org/web/20160910063328/https://www.highbeam.com/doc/1G1-132081136.html |url-status= dead |archive-date= 10 September 2016 |title=Does vitamin E cause congestive heart failure? (Literature Review & Commentary) | vauthors = Gaby AR |date=2005 |work=Townsend Letter for Doctors and Patients }}</ref><ref name="Higdon">{{cite web | vauthors = Higdon J | date = 2011 | url = http://lpi.oregonstate.edu/infocenter/vitamins/vitaminE/ | title = Vitamin E recommendations | work = Linus Pauling Institute's Micronutrient Information Center }}</ref>
|many fruits and vegetables, nuts and seeds, and seed oils
|-
! rowspan="2" |[[vitamin K|K]]
! [[vitamin K1|K<sub>1</sub>]]
| [[phylloquinone]]
| {{CellCategory |1 |fat |align=mc}}
| rowspan="2" | AI: 110&nbsp;μg/120&nbsp;μg
| rowspan="2" | [[bleeding diathesis]]
| rowspan="2" | decreased anticoagulation effect of [[warfarin]].<ref>{{cite journal | vauthors = Rohde LE, de Assis MC, Rabelo ER | title = Dietary vitamin K intake and anticoagulation in elderly patients | journal = Current Opinion in Clinical Nutrition and Metabolic Care | volume = 10 | issue = 1 | pages = 120–124 | date = January 2007 | pmid = 17143047 | doi = 10.1097/MCO.0b013e328011c46c | s2cid = 20484616 }}</ref>
| leafy green vegetables such as spinach
|-
![[vitamin K2|K<sub>2</sub>]]
|[[menaquinone]]
| {{CellCategory |1 |fat |align=mc}}
|poultry and eggs, ''[[nattō]]'', beef, pork, or fish
|}

==History==
The value of eating certain foods to maintain health was recognized long before vitamins were identified. The [[ancient Egyptians]] knew that feeding [[liver (food)|liver]] to a person may help with [[night blindness]], an illness now known to be caused by a [[vitamin A]] deficiency.<ref name="Challem"/> The advance of ocean voyages during the [[Age of Discovery]] resulted in prolonged periods without access to fresh fruits and vegetables, and made illnesses from vitamin deficiency common among ships' crews.<ref>{{cite book | vauthors = Jacob RA | title = Three eras of vitamin C discovery | chapter = Introduction: Three Eras of Vitamin C Discovery | volume = 25 | pages = 1–16 | date = 1996 | pmid = 8821966 | doi = 10.1007/978-1-4613-0325-1_1 | isbn = 978-1-4613-7998-0 | series = Subcellular Biochemistry }}</ref>

{| class="wikitable sortable" style = "float:right; font-size:90%; margin-left:15px"
|+ The discovery dates of the vitamins and their sources
|- class="hintergrundfarbe6"
! Year of discovery !! Vitamin !! Food source
|-
| 1913 || Vitamin A (Retinol) || [[Cod liver oil]]
|-
| 1910 || Vitamin B<sub>1</sub> (Thiamine) || [[Rice bran]]
|-
| 1920 || Vitamin C (Ascorbic acid) || [[Citrus]], most fresh foods
|-
| 1920 || Vitamin D (Calciferol) || Cod liver oil
|-
| 1920 || Vitamin B<sub>2</sub> (Riboflavin) || [[Meat]], [[dairy products]], [[Egg (food)|egg]]s
|-
| 1922 || Vitamin E (Tocopherol)|| [[Wheat germ oil]], <br /> unrefined vegetable oils
|-
| 1929 || Vitamin K<sub>1</sub> ([[Phylloquinone]]) || [[Leaf vegetable]]s
|-
| 1931 || Vitamin B<sub>5</sub> (Pantothenic acid) || Meat, [[whole grain]]s, <br />in many foods
|-
| 1934 || Vitamin B<sub>6</sub> (Pyridoxine) || Meat, dairy products
|-
| 1936 || Vitamin B<sub>7</sub> ([[Biotin]])<ref>{{Cite journal| vauthors = Kögl F, Tönnis B |date=1936 |volume=242|issue=1–2|pages=43–73|doi=10.1515/bchm2.1936.242.1-2.43|title=Über das Bios-Problem. Darstellung von krystallisiertem Biotin aus Eigelb. 20. Mitteilung über pflanzliche Wachstumsstoffe|journal=Hoppe-Seyler's Zeitschrift für Physiologische Chemie}}</ref> || Meat, dairy products, Eggs
|-
| 1936 || Vitamin B<sub>3</sub> (Niacin) || Meat, [[grain]]s
|-
| 1941 || Vitamin B<sub>9</sub> (Folic acid) || Leaf vegetables
|-
| 1948 || [[Vitamin B12|Vitamin B<sub>12</sub>]] (Cobalamins) || Meat, organs ([[Liver (food)|Liver]]), Eggs  
|-
|}

In 1747, the [[Scotland|Scottish]] [[surgeon]] [[James Lind (physician)|James Lind]] discovered that [[citrus]] foods helped prevent scurvy, a particularly deadly disease in which [[collagen]] is not properly formed, causing poor wound healing, bleeding of the [[gingiva|gums]], severe pain, and death.<ref name="Challem">Jack Challem (1997).[http://www.thenutritionreporter.com/history_of_vitamins.html "The Past, Present and Future of Vitamins"] {{Webarchive|url=https://web.archive.org/web/20051130103653/http://www.thenutritionreporter.com/history_of_vitamins.html |date=30 November 2005 }}</ref> In 1753, Lind published his ''Treatise on the Scurvy'', which recommended using [[lemon]]s and [[Lime (fruit)|lime]]s to avoid [[scurvy]], which was adopted by the British [[Royal Navy]]. This led to the nickname ''[[limey]]'' for British sailors. However, during the 19th century, limes grown in the West Indies were substituted for lemons; these were subsequently found to be much lower in vitamin C.<ref>{{Cite journal |date=1918 |title=The relative content of antiscorbutic principle in limes and lemons, together with some new facts and some old observations concerning the value of "lime juice" in the prevention of scurvy. |url=https://linkinghub.elsevier.com/retrieve/pii/S0140673600590266 |journal=The Lancet |language=en |volume=192 |issue=4970 |pages=735–738 |doi=10.1016/S0140-6736(00)59026-6|url-access=subscription }}</ref> As a result, Arctic expeditions continued to be plagued by scurvy and other [[deficiency disease]]s. In the early 20th century, when [[Robert Falcon Scott]] made his two expeditions to the [[Antarctic]], the prevailing medical theory was that scurvy was caused by "tainted" [[canning|canned food]].<ref>{{cite journal | vauthors = Lewis HE | title = Medical aspects of polar exploration: sixtieth anniversary of Scott's last expedition. State of knowledge about scurvy in 1911 | journal = Proceedings of the Royal Society of Medicine | volume = 65 | issue = 1 | pages = 39–42 | date = January 1972 | pmc = 1644345 | doi = 10.1177/003591577206500116 | pmid = 4552518 }}</ref>

In 1881, [[Russian Empire|Russia]]n medical doctor [[Nikolai Lunin (scientist)|Nikolai Lunin]] studied the effects of scurvy at the [[University of Tartu]]. He fed mice an artificial mixture of all the separate constituents of milk known at that time, namely the [[protein]]s, [[fat]]s, [[carbohydrate]]s, and [[salt (chemistry)|salt]]s. The mice that received only the individual constituents died, while the mice fed by milk itself developed normally. He made a conclusion that "a natural food such as milk must therefore contain, besides these known principal ingredients, small quantities of unknown substances essential to life." However, his conclusions were rejected by his advisor, [[Gustav von Bunge]].<ref name=Gratzer>{{cite book| vauthors = Gratzer W |chapter=9. The quarry run to earth|title=Terrors of the table: the curious history of nutrition|date=2006|publisher=Oxford University Press|location=Oxford|isbn=978-0199205639|chapter-url=https://books.google.com/books?id=W2g8vHsjpjwC&pg=PT182|access-date=5 November 2015}}</ref> A similar result by [[Cornelis Adrianus Pekelharing]] appeared in Dutch medical journal ''[[Nederlands Tijdschrift voor Geneeskunde]]'' in 1905,{{efn|{{cite journal | vauthors = Pekelharing CA |title=Over onze kennis van de waarde der voedingsmiddelen uit chemische fabrieken |journal=Nederlands Tijdschrift voor Geneeskunde |date=1905 |volume=41 |pages=111–124 |trans-title=About our knowledge of the value of food products from chemical factories |language=Dutch}}<ref name="semba-99">{{cite journal | vauthors = Semba RD | title = Vitamin A as "anti-infective" therapy, 1920–1940 | journal = The Journal of Nutrition | volume = 129 | issue = 4 | pages = 783–791 | date = April 1999 | pmid = 10203551 | doi = 10.1093/jn/129.4.783 | doi-access = free | author1-link = Richard David Semba }}</ref>}} but it was not widely reported.<ref name=Gratzer/>

In [[East Asia]], where polished [[white rice]] was the common staple food of the middle class, [[beriberi]] resulting from lack of vitamin B<sub>1</sub> was [[Endemic (epidemiology)|endemic]]. In 1884, [[Takaki Kanehiro]], a British-trained medical doctor of the [[Imperial Japanese Navy]], observed that beriberi was endemic among low-ranking crew who often ate nothing but rice, but not among officers who consumed a Western-style diet. With the support of the Japanese navy, he experimented using crews of two [[battleship]]s; one crew was fed only white rice, while the other was fed a diet of meat, fish, barley, rice, and beans. The group that ate only white rice documented 161 crew members with beriberi and 25 deaths, while the latter group had only 14 cases of beriberi and no deaths. This convinced Takaki and the Japanese Navy that diet was the cause of beriberi, but they mistakenly believed that sufficient amounts of protein prevented it.<ref name=Rosenfeld>{{cite journal | vauthors = Rosenfeld L | title = Vitamine – vitamin. The early years of discovery | journal = Clinical Chemistry | volume = 43 | issue = 4 | pages = 680–685 | date = April 1997 | pmid = 9105273 | doi = 10.1093/clinchem/43.4.680 | doi-access = free }}</ref> That diseases could result from some dietary deficiencies was further investigated by [[Christiaan Eijkman]], who in 1897 discovered that feeding unpolished [[rice]] instead of the polished variety to chickens helped to prevent a kind of [[polyneuritis]] that was the equivalent of beriberi.<ref name=Wendt>{{cite journal| vauthors = Wendt D |title=Packed full of questions: Who benefits from dietary supplements?|journal=Distillations Magazine|date=2015|volume=1|issue=3|pages=41–45|url=https://www.sciencehistory.org/distillations/magazine/packed-full-of-questions|access-date=22 March 2018}}</ref> The following year, [[Frederick Hopkins]] postulated that some foods contained "accessory factors"&nbsp;– in addition to proteins, carbohydrates, fats ''etc.''&nbsp;– that are necessary for the functions of the human body.<ref name="Challem"/>

[[File:J. C. Drummond, The Nomenclature of the So-called Accessory Food Factors (Vitamins), 1920.png|thumb|[[Jack Drummond]]'s single-paragraph article in 1920 which provided structure and nomenclature used today for vitamins]]

==="Vitamine" to vitamin===
In 1910, the first vitamin complex was isolated by Japanese scientist [[Umetaro Suzuki]], who succeeded in extracting a water-soluble complex of micronutrients from rice bran and named it [[aberic acid]] (later ''Orizanin''). He published this discovery in a Japanese scientific journal.<ref>{{cite journal|title=Active constituent of rice grits preventing bird polyneuritis|journal=Tokyo Kagaku Kaishi |date=1911|author=Suzuki, U.|author2=Shimamura, T.|volume=32|pages=4–7, 144–146, 335–358|url=https://www.jstage.jst.go.jp/browse/nikkashi1880/32/1/_contents|doi=10.1246/nikkashi1880.32.4 |doi-access=free}}</ref> When the article was translated into German, the translation failed to state that it was a newly discovered nutrient, a claim made in the original Japanese article, and hence his discovery failed to gain publicity. In 1912 Polish-born biochemist [[Casimir Funk]], working in London, isolated the same complex of micronutrients and proposed the complex be named "vitamine".<ref name = "Funk" /> It was later to be known as vitamin B<sub>3</sub> (niacin), though he described it as "anti-beri-beri-factor" (which would today be called thiamine or vitamin B<sub>1</sub>). Funk proposed the hypothesis that other diseases, such as rickets, pellagra, coeliac disease, and scurvy could also be cured by vitamins. [[Maximilian Nierenstein|Max Nierenstein]] a friend and Reader of Biochemistry at Bristol University reportedly suggested the "vitamine" name (from "vital amine").<ref name= "Combs_2008">{{cite book | vauthors = Combs G | chapter = Discovery of Vitamins |title = The vitamins: fundamental aspects in nutrition and health| chapter-url = https://books.google.com/books?id=1CMHiWum0Y4C&pg=PA16|isbn = 9780121834937 |date = 2008| publisher=Elsevier }}</ref><ref>Funk, C. and Dubin, H. E. (1922). ''The Vitamines''. Baltimore: Williams and Wilkins Company.</ref> The name soon became synonymous with Hopkins' "accessory factors", and, by the time it was shown that not all vitamins are [[amine]]s, the word was already ubiquitous. In 1920, [[Jack Cecil Drummond]] proposed that the final "e" be dropped to deemphasize the "amine" reference, hence "vitamin", after researchers began to suspect that not all "vitamines" (in particular, vitamin A) have an amine component.<ref name=Rosenfeld/>

===Nobel Prizes for vitamin research===
The Nobel Prize for Chemistry for 1928 was awarded to [[Adolf Windaus]] "for his studies on the constitution of the sterols and their connection with vitamins", the first person to receive an award mentioning vitamins, even though it was not specifically about vitamin D.<ref>{{cite journal | vauthors = Wolf G | title = The discovery of vitamin D: the contribution of Adolf Windaus | journal = The Journal of Nutrition | volume = 134 | issue = 6 | pages = 1299–1302 | date = June 2004 | pmid = 15173387 | doi = 10.1093/jn/134.6.1299 | doi-access = free }}</ref>

The [[Nobel Prize in Physiology or Medicine]] for 1929 was awarded to Christiaan Eijkman and [[Frederick Gowland Hopkins]] for their contributions to the discovery of vitamins. Thirty-five years earlier, Eijkman had observed that chickens fed polished white rice developed neurological symptoms similar to those observed in military sailors and soldiers fed a rice-based diet, and that the symptoms were reversed when the chickens were switched to whole-grain rice. He called this "the anti-beriberi factor", which was later identified as vitamin B<sub>1</sub>, thiamine.<ref name=Carpenter>{{cite web | vauthors = Carpenter K |title = The Nobel Prize and the Discovery of Vitamins |url = http://nobelprize.org/nobel_prizes/medicine/articles/carpenter/index.html |publisher = Nobelprize.org |date = 22 June 2004 |access-date = 5 October 2009}}</ref>

In 1930, [[Paul Karrer]] elucidated the correct structure for [[beta-carotene]], the main precursor of vitamin A, and identified other [[carotenoids]]. Karrer and [[Norman Haworth]] confirmed Albert Szent-Györgyi's discovery of [[ascorbic acid]] and made significant contributions to the chemistry of [[flavins]], which led to the identification of [[lactoflavin]]. For their investigations on carotenoids, flavins and vitamins A and B<sub>2</sub>, they both received the [[Nobel Prize in Chemistry]] in 1937.<ref name="Karrer">{{cite web|website=Nobelprize.org|url=https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1937/karrer-bio.html|title=Paul Karrer-Biographical|access-date=8 January 2013}}</ref>

In 1931, [[Albert Szent-Györgyi]] and a fellow researcher [[Joseph Svirbely]] suspected that "hexuronic acid" was actually [[vitamin C]], and gave a sample to [[Charles Glen King]], who proved its ability to counter scurvy in his long-established [[guinea pig]] scorbutic assay. In 1937, Szent-Györgyi was awarded the Nobel Prize in Physiology or Medicine for his discovery. In 1943, [[Edward Adelbert Doisy]] and [[Henrik Dam]] were awarded the Nobel Prize in Physiology or Medicine for their discovery of [[vitamin K]] and its chemical structure.

In 1938, [[Richard Kuhn]] was awarded the Nobel Prize in Chemistry for his work on carotenoids and vitamins, specifically B<sub>2</sub> and B<sub>6</sub>.<ref name="Kuhn">{{cite web|url=https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1938/index.html|title=The Nobel Prize in Chemistry 1938|access-date=5 July 2018|website=Nobelprize.org}}</ref>

Five people have been awarded [[Nobel Prize]]s for direct and indirect studies of vitamin B<sub>12</sub>: [[George Whipple]], [[George Minot]] and [[William P. Murphy]] (1934), [[Alexander R. Todd]] (1957), and [[Dorothy Hodgkin]] (1964).<ref name=NobelPrizeRef>{{cite web|url=https://www.nobelprize.org/nobel_prizes/themes/medicine/carpenter/|title=The Nobel Prize and the Discovery of Vitamins|website=www.nobelprize.org|access-date=15 February 2018|archive-url=https://web.archive.org/web/20180116004953/https://www.nobelprize.org/nobel_prizes/themes/medicine/carpenter/|archive-date=16 January 2018|url-status=live}}</ref>

In 1967, [[George Wald]], [[Ragnar Granit]] and [[Haldan Keffer Hartline]] were awarded the Nobel Prize in Physiology and Medicine  "...for their discoveries concerning the primary physiological and chemical visual processes in the eye." Wald's contribution was discovering the role vitamin A had in the process.<ref name= Carpenter/><ref name="nobel-1967">{{cite web|title=The Nobel Prize in Physiology or Medicine 1967|url=http://www.nobelprize.org/nobel_prizes/medicine/laureates/1967/index.html|publisher=Nobel Foundation|access-date=28 July 2007|archive-url=https://web.archive.org/web/20131204095703/http://www.nobelprize.org/nobel_prizes/medicine/laureates/1967/index.html|archive-date=4 December 2013|url-status=live}}</ref>

===History of promotional marketing===
Once discovered, vitamins were actively promoted in articles and advertisements in ''[[McCall's]]'', ''[[Good Housekeeping]]'', and other media outlets.<ref name="Wendt" /> Marketers enthusiastically promoted [[cod-liver oil]], a source of vitamin D, as "bottled sunshine", and bananas as a "natural vitality food".<ref name="Yeast"/> They promoted foods such as [[yeast]] cakes, a source of B vitamins, on the basis of scientifically determined nutritional value, rather than taste or appearance.<ref name="Yeast">{{cite journal|author1=Price C|date=Fall 2015|title=The healing power of compressed yeast|url=https://www.sciencehistory.org/distillations/magazine/the-healing-power-of-compressed-yeast|journal=Distillations Magazine|volume=1|issue=3|pages=17–23|access-date=20 March 2018}}</ref> In 1942, when flour [[food fortification|enrichment]] with nicotinic acid began, a headline in the popular press said "Tobacco in Your Bread." In response, the Council on Foods and Nutrition of the [[American Medical Association]] approved of the [[Food and Nutrition Board]]'s new names ''niacin'' and ''niacin amide'' for use primarily by non-scientists. It was thought appropriate to choose a name to dissociate nicotinic acid from [[nicotine]], to avoid the perception that vitamins or niacin-rich food contains nicotine, or that cigarettes contain vitamins. The resulting name ''niacin'' was derived from ''{{strong|ni}}cotinic {{strong|ac}}id'' + ''vitam{{strong|in}}''.<ref>{{cite journal|title=Niacin and Niacin Amide| date=7 March 1942|volume=118|issue=10|doi=10.1001/jama.1942.02830100049011|journal=Journal of the American Medical Association|page=819}}</ref><ref>{{cite journal|title=Niacin and Nicotinic Acid|date=7 March 1942|volume=118|issue=10|doi=10.1001/jama.1942.02830100053014|journal=Journal of the American Medical Association|page=823}}</ref> Researchers also focused on the need to ensure adequate nutrition, especially to compensate for what was lost in the manufacture of [[processed foods]].<ref name="Wendt" /> 

Robert W. Yoder is credited with first using the term ''vitamania'', in 1942, to describe the appeal of relying on nutritional supplements rather than on obtaining vitamins from a varied diet of foods. The continuing preoccupation with a healthy lifestyle led to an obsessive consumption of vitamins and multi-vitamins, the beneficial effects of which are questionable.<ref name="Price" /> As one example, in the 1950s, the [[Wonder Bread]] company sponsored the [[Howdy Doody]] television show, with host [[Buffalo Bob Smith]] telling the audience, "Wonder Bread builds strong bodies 8 ways", referring to the number of [[Food additive|added nutrients]].<ref>{{cite web| url=https://americacomesalive.com/wonder-bread/| title=Wonder Bread: The Most Famous White Bread| vauthors = Kelly K | date= 27 October 2021| access-date=26 February 2022| website=America Comes Alive}}</ref>

==Etymology==
The term "vitamin" was derived from "vitamine", a [[blend word|portmanteau]] coined in 1912 by the [[biochemist]] Casimir Funk while working at the [[Lister Institute of Preventive Medicine]].<ref name = "Funk">{{cite journal | vauthors = Funk C |title=The etiology of the deficiency diseases. Beri-beri, polyneuritis in birds, epidemic dropsy, scurvy, experimental scurvy in animals, infantile scurvy, ship beri-beri, pellagra |journal=Journal of State Medicine |date=1912 |volume=20 |pages=341–368 |url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015069802166&view=1up&seq=351}} The word "vitamine" is coined on p. 342: "It is now known  that all these diseases, with the exception of pellagra, can be prevented and cured by the addition of certain preventative substances; the deficient substances, which are of the nature of organic bases, we will call "vitamines"; and we will speak of a beri-beri or scurvy vitamine, which means a substance preventing the special disease."</ref> Funk created the name from ''vital'' and ''amine'', because it appeared that these organic micronutrient food factors that prevent beriberi and perhaps other similar dietary-deficiency diseases were required for life, hence "vital", and were chemical amines, hence "amine". This was true of [[thiamine]], but after it was found that vitamin C and other such micronutrients were not amines, the word was shortened to "vitamin" in English.<ref name= "Combs_2008" />

==Classification==
Vitamins are classified as either [[Hydrophilicity|water-soluble]] or [[lipophilicity|fat-soluble]]. In humans there are 13 vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C). Water-soluble vitamins dissolve easily in water and, in general, are readily excreted from the body, to the degree that urinary output is a strong predictor of vitamin consumption.<ref name="pmid18635909">{{cite journal | vauthors = Fukuwatari T, Shibata K | title = Urinary water-soluble vitamins and their metabolite contents as nutritional markers for evaluating vitamin intakes in young Japanese women | journal = Journal of Nutritional Science and Vitaminology | volume = 54 | issue = 3 | pages = 223–229 | date = June 2008 | pmid = 18635909 | doi = 10.3177/jnsv.54.223 | doi-access = free }}</ref> Because they are not as readily stored, more consistent intake is important.<ref name="urlWater-Soluble Vitamins">{{cite web|url=http://www.ext.colostate.edu/PUBS/FOODNUT/09312.html|vauthors=Bellows L, Moore R|work=Colorado State University|title=Water-Soluble Vitamins|access-date=7 December 2008|archive-date=25 September 2015|archive-url=https://web.archive.org/web/20150925060831/http://www.ext.colostate.edu/pubs/foodnut/09312.html|url-status=dead}}</ref> Fat-soluble vitamins are absorbed through the [[gastrointestinal tract]] with the help of [[lipid]]s (fats). Vitamins A and D can accumulate in the body, which can result in dangerous [[hypervitaminosis]]. Fat-soluble vitamin deficiency due to malabsorption is of particular significance in [[cystic fibrosis]].<ref name="pmid18812835">{{cite journal | vauthors = Maqbool A, Stallings VA | title = Update on fat-soluble vitamins in cystic fibrosis | journal = Current Opinion in Pulmonary Medicine | volume = 14 | issue = 6 | pages = 574–581 | date = November 2008 | pmid = 18812835 | doi = 10.1097/MCP.0b013e3283136787 | s2cid = 37143703 }}</ref>

==Anti-vitamins==
{{Main|Antinutrient}}
Anti-vitamins are chemical compounds that inhibit the absorption or actions of vitamins. For example, [[avidin]] is a protein in raw egg whites that inhibits the absorption of [[biotin]]; it is deactivated by cooking.<ref>{{cite journal | vauthors = Roth KS | title = Biotin in clinical medicine—a review | journal = The American Journal of Clinical Nutrition | volume = 34 | issue = 9 | pages = 1967–1974 | date = September 1981 | pmid = 6116428 | doi = 10.1093/ajcn/34.9.1967 }}</ref> Pyrithiamine, a synthetic compound, has a molecular structure similar to thiamine, [[vitamin B1|vitamin B<sub>1</sub>]], and inhibits the [[enzyme]]s that use thiamine.<ref>{{cite journal | vauthors = Rindi G, Perri V | title = Uptake of pyrithiamine by tissue of rats | journal = The Biochemical Journal | volume = 80 | issue = 1 | pages = 214–216 | date = July 1961 | pmid = 13741739 | pmc = 1243973 | doi = 10.1042/bj0800214 }}</ref>

==Biochemical functions==
Each vitamin is typically used in multiple reactions, and therefore most have multiple functions.<ref name="Kutsky">Kutsky, R.J. (1973). ''Handbook of Vitamins and Hormones''. New York: Van Nostrand Reinhold, {{ISBN|0-442-24549-1}} {{page?|date=July 2024}}</ref>

===On fetal growth and childhood development===
{{main|Nutrition and pregnancy}}
Vitamins are essential for the normal growth and development of a multicellular organism. Using the genetic blueprint inherited from its parents, a [[fetus]] [[prenatal development|develop]]s from the nutrients it absorbs. It requires certain vitamins and minerals to be present at certain times.<ref name="Wilson2015" /> These nutrients facilitate the chemical reactions that produce among other things, [[skin]], [[bone]], and [[muscle]]. If there is serious deficiency in one or more of these nutrients, a child may develop a deficiency disease. Even minor deficiencies may cause permanent damage.<ref>Gavrilov, Leonid A. (10 February 2003) [https://www.fightaging.org/archives/2003/02/pieces-of-the-puzzle-aging-research-today-and-tomorrow.php "Pieces of the Puzzle: Aging Research Today and Tomorrow"]. fightaging.org</ref>

===On adult health maintenance===
Once growth and development are completed, vitamins remain essential nutrients for the healthy maintenance of the cells, tissues, and organs that make up a multicellular organism; they also enable a multicellular life form to efficiently use chemical energy provided by food it eats, and to help process the proteins, carbohydrates, and fats required for [[cellular respiration]].<ref name="Bender" />

== Intake ==

===Sources===
For the most part, vitamins are obtained from the diet, but some are acquired by other means: for example, microorganisms in the [[gut flora]] produce vitamin K and biotin; and one form of vitamin D is synthesized in skin cells when they are exposed to a certain wavelength of ultraviolet light present in [[sunlight]]. Humans can produce some vitamins from precursors they consume: for example, vitamin A is synthesized from [[beta carotene]]; and [[Niacin (nutrient)|niacin]] is synthesized from the [[amino acid]] [[tryptophan]].<ref name="DRI-Niacin">{{cite book|title=Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline|last1=Institute of Medicine|publisher=The National Academies Press|year=1998|isbn=978-0-309-06554-2|location=Washington, DC|pages=123–149|chapter=Niacin|access-date=29 August 2018|chapter-url=https://www.nap.edu/read/6015/chapter/8|author1-link=Institute of Medicine}}</ref> Vitamin C can be synthesized by some species but not by others. [[Vitamin B12|Vitamin B<sub>12</sub>]] is the only vitamin or nutrient not available from plant sources. The Food Fortification Initiative lists countries which have mandatory fortification programs for vitamins folic acid, niacin, vitamin A and vitamins B<sub>1</sub>, B<sub>2</sub> and B<sub>12</sub>.<ref name="FoodFortif" />

===Deficient intake===
{{See also|Vitamin deficiency}}

The [[human body|body's]] stores for different vitamins vary widely; vitamins A, D, and B<sub>12</sub> are stored in significant amounts, mainly in the [[liver]],<ref name="Merck" /> and an adult's diet may be deficient in vitamins A and D for many months and B<sub>12</sub> in some cases for years, before developing a deficiency condition. However, vitamin B<sub>3</sub> (niacin and niacinamide) is not stored in significant amounts, so stores may last only a couple of weeks.<ref name="GOVa" /><ref name="Merck" /> For vitamin C, the first symptoms of scurvy in experimental studies of complete vitamin C deprivation in humans have varied widely, from a month to more than six months, depending on previous dietary history that determined body stores.<ref>{{cite journal | vauthors = Pemberton J | title = Medical experiments carried out in Sheffield on conscientious objectors to military service during the 1939–45 war | journal = International Journal of Epidemiology | volume = 35 | issue = 3 | pages = 556–558 | date = June 2006 | pmid = 16510534 | doi = 10.1093/ije/dyl020 | doi-access = free }}</ref>

Deficiencies of vitamins are classified as either primary or secondary. A primary deficiency occurs when an organism does not get enough of the vitamin in its food. A secondary deficiency may be due to an underlying disorder that prevents or limits the absorption or use of the vitamin, due to a "lifestyle factor", such as smoking, excessive alcohol consumption, or the use of medications that interfere with the absorption or use of the vitamin.<ref name="Merck" /> People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency, but may be consuming less than the recommended amounts; a national food and supplement survey conducted in the US over 2003–2006 reported that over 90% of individuals who did not consume vitamin supplements were found to have inadequate levels of some of the essential vitamins, notably vitamins D and E.<ref name=":03">{{cite journal | vauthors = Bailey RL, Fulgoni VL, Keast DR, Dwyer JT | title = Examination of vitamin intakes among US adults by dietary supplement use | journal = Journal of the Academy of Nutrition and Dietetics | volume = 112 | issue = 5 | pages = 657–663.e4 | date = May 2012 | pmid = 22709770 | pmc = 3593649 | doi = 10.1016/j.jand.2012.01.026 }}</ref>

Well-researched human vitamin deficiencies involve thiamine (beriberi), niacin ([[pellagra]]),<ref name="Wendt" /> vitamin C (scurvy), folate (neural tube defects) and vitamin D (rickets).<ref name="Price">{{cite book|url=https://books.google.com/books?id=IPcVBAAAQBAJ&pg=PR96|title=Vitamania: Our obsessive quest for nutritional perfection| vauthors = Price C |date=2015|publisher=Penguin Press|isbn=978-1594205040|name-list-style=vanc}}</ref> In much of the developed world these deficiencies are rare due to an adequate supply of food and the addition of vitamins to common foods.<ref name="Merck" /> In addition to these classical vitamin deficiency diseases, some evidence has also suggested links between vitamin deficiency and a number of different disorders.<ref>{{cite journal | vauthors = Lakhan SE, Vieira KF | title = Nutritional therapies for mental disorders | journal = Nutrition Journal | volume = 7 | pages = 2 | date = January 2008 | pmid = 18208598 | pmc = 2248201 | doi = 10.1186/1475-2891-7-2 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Boy E, Mannar V, Pandav C, de Benoist B, Viteri F, Fontaine O, Hotz C | title = Achievements, challenges, and promising new approaches in vitamin and mineral deficiency control | journal = Nutrition Reviews | volume = 67 | issue = Suppl 1 | pages = S24–S30 | date = May 2009 | pmid = 19453674 | doi = 10.1111/j.1753-4887.2009.00155.x }}
</ref>

===Excess intake===
{{See also|Hypervitaminosis}}

Some vitamins have documented acute or chronic toxicity at larger intakes, which is referred to as hypertoxicity. The European Union and the governments of several countries have established [[Tolerable upper intake levels|tolerable upper intake levels]] (ULs) for those vitamins which have documented toxicity (see table).<ref name="DRITable" /><ref name="EFSA" /><ref name="JapanDRI" /> The likelihood of consuming too much of any vitamin from food is remote, but excessive intake ([[vitamin poisoning]]) from dietary supplements does occur. In 2016, overdose exposure to all formulations of vitamins and multi-vitamin/mineral formulations was reported by 63,931 individuals to the [[American Association of Poison Control Centers]] with 72% of these exposures in children under the age of five.<ref>{{cite journal | vauthors = Gummin DD, Mowry JB, Spyker DA, Brooks DE, Fraser MO, Banner W | title = 2016 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 34th Annual Report | journal = Clinical Toxicology | volume = 55 | issue = 10 | pages = 1072–1252 | date = December 2017 | pmid = 29185815 | doi = 10.1080/15563650.2017.1388087 | s2cid = 28547821 | doi-access = free }}</ref> In the US, analysis of a national diet and supplement survey reported that about 7% of adult supplement users exceeded the UL for folate and 5% of those older than age 50 years exceeded the UL for vitamin A.<ref name=":03"/>

===Effects of cooking===
The [[USDA]] has conducted extensive studies on the percentage losses of various nutrients from food types and cooking methods.<ref>{{Cite web|url=https://www.ars.usda.gov/ARSUserFiles/80400525/Data/retn/retn06.pdf|title = USDA Table of Nutrient Retention Factors, Release 6|date = Dec 2007|website = USDA|publisher = USDA.}}</ref> Some vitamins may become more "bio-available" – that is, usable by the body – when foods are cooked.<ref>[http://www.beyondveg.com/tu-j-l/raw-cooked/raw-cooked-2f.shtml Comparison of Vitamin Levels in Raw Foods vs. Cooked Foods]. Beyondveg.com. Retrieved on 3 August 2013.</ref> The table below shows whether various vitamins are susceptible to loss from heat—such as heat from boiling, steaming, frying, etc. The effect of cutting vegetables can be seen from exposure to air and light. Water-soluble vitamins such as B and C dissolve into the water when a vegetable is boiled, and are then lost when the water is discarded.<ref>[http://www.beyondveg.com/tu-j-l/raw-cooked/raw-cooked-2e.shtml Effects of Cooking on Vitamins (Table)]. Beyondveg.com. Retrieved on 3 August 2013.</ref>

{| class="wikitable sortable" border="1" |-
! rowspan="2" |Vitamin
! colspan="4" |'''Is substance susceptible to losses under given condition?'''
|-
!Soluble in Water
!Air Exposure
!Light Exposure
!Heat Exposure
|-
|Vitamin A
| no
| partially
| partially
| relatively stable
|-
|Vitamin C
| very unstable
| yes
| no
| no
|-
| Vitamin D
| no
| no
| no
| no
|-
| Vitamin E
| no
| yes
| yes
| no
|-
|Vitamin K
| no
| no
| yes
| no
|-
|Thiamine (B<sub>1</sub>)
| highly
| no
| ?
| > 100&nbsp;°C
|-
|Riboflavin (B<sub>2</sub>)
| slightly
| no
| in solution
| no
|-
|Niacin (B<sub>3</sub>)
| yes
| no
| no
| no
|-
|Pantothenic Acid (B<sub>5</sub>)
| quite stable
| no
| no
| yes
|-
|Vitamin B<sub>6</sub>
| yes
| ?
| yes
| < 160&nbsp;°C
|-
|Biotin (B<sub>7</sub>)
| somewhat
| ?
| ?
| no
|-
|Folic Acid (B<sub>9</sub>)
| yes
| ?
| when dry
| at high temp
|-
|Cobalamin (B<sub>12</sub>)
| yes
| ?
| yes
| no
|}

==Recommended levels==
In setting human nutrient guidelines, government organizations do not necessarily agree on amounts needed to avoid deficiency or maximum amounts to avoid the risk of toxicity.<ref name="EFSA">{{citation| title= Tolerable Upper Intake Levels For Vitamins And Minerals| publisher= European Food Safety Authority| year= 2006| url = http://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf}}</ref><ref name="DRITable">[http://www.nationalacademies.org/hmd/~/media/Files/Activity%20Files/Nutrition/DRI-Tables/5Summary%20TableTables%2014.pdf?la=en Dietary Reference Intakes (DRIs)] {{Webarchive|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 |date=11 September 2018 }} Food and Nutrition Board, Institute of Medicine, National Academies</ref><ref name="JapanDRI">[http://www.nibiohn.go.jp/eiken/info/pdf/dris2010en.pdf Dietary Reference Intakes for Japanese (2010)] National Institute of Health and Nutrition, Japan</ref> For example, for vitamin C, recommended intakes range from 40&nbsp;mg/day in India<ref name="NIN">{{cite web |url=http://icmr.nic.in/final/rda-2010.pdf |title=Nutrient Requirements and Recommended Dietary Allowances for Indians: A Report of the Expert Group of the Indian Council of Medical Research|pages=283–295 |date=2009 |url-status=live |archive-url=https://web.archive.org/web/20160615094048/http://icmr.nic.in/final/RDA-2010.pdf |archive-date=15 June 2016  }}</ref> to 155&nbsp;mg/day for the European Union.<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=28 August 2017 }}</ref> The table below shows U.S. Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for vitamins, PRIs for the European Union (same concept as RDAs), followed by what three government organizations deem to be the safe upper intake. RDAs are set higher than EARs to cover people with higher than average needs. Adequate Intakes (AIs) are set when there is not sufficient information to establish EARs and RDAs. Governments are slow to revise information of this nature. For the U.S. values, with the exception of calcium and vitamin D, all of the data date to 1997–2004.<ref name="DRI">Dietary Reference Intakes: The Essential Guide to Nutrient Requirements, published by the Institute of Medicine's Food and Nutrition Board, currently available online at {{cite web |url=http://fnic.nal.usda.gov/dietary-guidance/dietary-reference-intakes/dri-reports |title=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>

All values are consumption per day:

{| class="wikitable"
|-
! rowspan="2" |Nutrient !! rowspan="2" |U.S. EAR<ref name="DRITable" />!! rowspan="2" |Highest U.S.<br />RDA or AI<ref name="DRITable" />!! rowspan="2" |Highest EU<br />PRI or AI<ref name="EFSA-Recommended" />!! colspan="3" |Upper limit (UL) !! rowspan="2" |Unit
|-
! U.S.<ref name="DRITable" />!! EU <ref name="EFSA" />!! Japan<ref name="JapanDRI" />
|-
|[[Vitamin A]]|| 625 || 900 || 1300 || 3000 || 3000 || 2700 || μg
|-
|[[Vitamin C]]|| 75 || 90 || 155 || 2000 || ND || ND || mg
|-
|[[Vitamin D]]|| 10 || 15 || 15 || 100 || 100 || 100 || μg
|-
|[[Vitamin K]]|| NE || 120 || 70 || ND || ND || ND || μg
|-
|[[Tocopherol|α-tocopherol]] (Vitamin E) || 12 || 15 || 13 || 1000 || 300 || 650–900 || mg
|-
|[[Thiamin]] (Vitamin B<sub>1</sub>) || 1.0 || 1.2 || 0.1&nbsp;mg/MJ || ND || ND || ND || mg
|-
|[[Riboflavin]] (Vitamin B<sub>2</sub>) || 1.1 || 1.3 || 2.0 || ND || ND || ND || mg
|-
|[[Niacin (nutrient)|Niacin]] (Vitamin B<sub>3</sub>) || 12 || 16 || 1.6&nbsp;mg/MJ || 35 || 10 || 60–85 || mg
|-
|[[Pantothenic acid]] (Vitamin B<sub>5</sub>) || NE || 5 || 7 || ND || ND || ND || mg
|-
|[[Vitamin B6|Vitamin B<sub>6</sub>]]|| 1.1 || 1.3 || 1.8 || 100 || 25 || 40–60 || mg
|-
|[[Biotin]] (Vitamin B<sub>7</sub>) || NE || 30 || 45 || ND || ND || ND || μg
|-
|[[Folate]] (Vitamin B<sub>9</sub>) || 320 || 400 || 600 || 1000 || 1000 || 900–1000|| μg
|-
|[[Cyanocobalamin]] (Vitamin B<sub>12</sub>) || 2.0 || 2.4 || 5.0 || ND || ND || ND || μg
|}

'''EAR''' US Estimated Average Requirements.

'''RDA''' US Recommended Dietary Allowances; higher for adults than for children, and may be even higher for women who are pregnant or lactating.

'''AI'''  US and EFSA Adequate Intake; AIs established when there is not sufficient information to set EARs and RDAs.

'''PRI''' Population Reference Intake is European Union equivalent of RDA; higher for adults than for children, and may be even higher for women who are pregnant or lactating. For Thiamin and Niacin the PRIs are expressed as amounts per MJ of calories consumed. MJ = megajoule = 239 food calories.

'''UL or Upper Limit'''  Tolerable upper intake levels.

'''ND'''  ULs have not been determined.

'''NE'''  EARs have not been established.

==Supplementation==
[[File:500 mg calcium supplements with vitamin D.jpg|thumb|upright=1.25|Calcium combined with vitamin D (as calciferol) supplement tablets with fillers.]]
In those who are otherwise healthy, there is little evidence that supplements have any benefits with respect to [[cancer]] or [[cardiovascular disease|heart disease]].<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 = 824–834 | date = December 2013 | pmid = 24217421 | doi = 10.7326/0003-4819-159-12-201312170-00729 | doi-access = free }}</ref><ref name="Moy2014">{{cite journal | vauthors = Moyer VA |author1-link=Virginia Moyer  | title = Vitamin, mineral, and multivitamin supplements for the primary prevention of cardiovascular disease and cancer: U.S. Preventive services Task Force recommendation statement | journal = Annals of Internal Medicine | volume = 160 | issue = 8 | pages = 558–564 | date = April 2014 | pmid = 24566474 | doi = 10.7326/M14-0198 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Jenkins DJ, Spence JD, Giovannucci EL, Kim YI, Josse R, Vieth R, Blanco Mejia S, Viguiliouk E, Nishi S, Sahye-Pudaruth S, Paquette M, Patel D, Mitchell S, Kavanagh M, Tsirakis T, Bachiri L, Maran A, Umatheva N, McKay T, Trinidad G, Bernstein D, Chowdhury A, Correa-Betanzo J, Del Principe G, Hajizadeh A, Jayaraman R, Jenkins A, Jenkins W, Kalaichandran R, Kirupaharan G, Manisekaran P, Qutta T, Shahid R, Silver A, Villegas C, White J, Kendall CW, Pichika SC, Sievenpiper JL | display-authors = 6 | title = Supplemental Vitamins and Minerals for CVD Prevention and Treatment | journal = Journal of the American College of Cardiology | volume = 71 | issue = 22 | pages = 2570–2584 | date = June 2018 | pmid = 29852980 | doi = 10.1016/j.jacc.2018.04.020 | doi-access = free }}</ref> Vitamin A and E supplements not only provide no health benefits for generally healthy individuals, but they may increase mortality, though the two large studies that support this conclusion included [[tobacco smoking|smokers]] for whom it was already known that beta-carotene supplements can be harmful.<ref name="Moy2014" /><ref>{{cite journal | vauthors = Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C | title = Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis | journal = JAMA | volume = 297 | issue = 8 | pages = 842–857 | date = February 2007 | pmid = 17327526 | doi = 10.1001/jama.297.8.842 }}</ref> A 2018 meta-analysis found no evidence that intake of vitamin D or calcium for community-dwelling elderly people reduced bone fractures.<ref>{{cite journal | vauthors = Zhao JG, Zeng XT, Wang J, Liu L | title = Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis | journal = JAMA | volume = 318 | issue = 24 | pages = 2466–2482 | date = December 2017 | pmid = 29279934 | pmc = 5820727 | doi = 10.1001/jama.2017.19344 }}</ref>

Europe has regulations that define limits of vitamin (and mineral) dosages for their safe use as dietary supplements. Most vitamins that are sold as dietary supplements are not supposed to exceed a maximum daily dosage referred to as the [[tolerable upper intake level]] (UL or Upper Limit). Vitamin products above these regulatory limits are not considered supplements and should be registered as prescription or non-prescription ([[over-the-counter drug]]s) due to their potential side effects. The European Union, United States and Japan establish ULs.<ref name="DRITable" /><ref name="EFSA" /><ref name="JapanDRI" />

[[Dietary supplement]]s often contain vitamins, but may also include other ingredients, such as minerals, herbs, and botanicals. [[Scientific evidence]] supports the benefits of dietary supplements for persons with certain health conditions.<ref name="Sup">[http://dietary-supplements.info.nih.gov/Health_Information/ODS_Frequently_Asked_Questions.aspx Use and Safety of Dietary Supplements] {{Webarchive|url=https://web.archive.org/web/20190327061553/https://dietary-supplements.info.nih.gov/Health_Information/ODS_Frequently_Asked_Questions.aspx |date=27 March 2019 }} NIH office of Dietary Supplements.</ref> In some cases, vitamin supplements may have unwanted effects, especially if taken before surgery, with other dietary supplements or medicines, or if the person taking them has certain health conditions.<ref name="Sup" /> They may also contain levels of vitamins many times higher, and in different forms, than one may ingest through food.
{{see also|Megavitamin therapy}}

===Governmental regulation===
Most countries place dietary supplements in a special category under the general umbrella of ''foods'', not drugs. As a result, the manufacturer, and not the government, has the responsibility of ensuring that its dietary supplement products are safe before they are marketed. Regulation of supplements varies widely by country. In the [[United States]], a dietary supplement is defined under the [[Dietary Supplement Health and Education Act]] of 1994.<ref>[https://web.archive.org/web/20010417213933/http://www.fda.gov/opacom/laws/dshea.html Legislation]. Fda.gov (15 September 2009). Retrieved on 12 November 2010.</ref> There is no FDA approval process for dietary supplements, and no requirement that manufacturers prove the safety or efficacy of supplements introduced before 1994.<ref name="Wendt" /><ref name="Price" /> The [[Food and Drug Administration]] must rely on its Adverse Event Reporting System to monitor adverse events that occur with supplements.<ref>{{cite web| title = Adverse Event Reporting System (AERS) | url = https://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Surveillance/AdverseDrugEffects/default.htm | archive-url = https://web.archive.org/web/20090603081828/http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Surveillance/AdverseDrugEffects/default.htm | url-status = dead | archive-date = 3 June 2009 | work = [[FDA]] | date = 20 August 2009 | access-date =  12 November 2010}}</ref>

In 2007, the US [[Code of Federal Regulations]] (CFR) Title 21, part III took effect, regulating Good Manufacturing Practices (GMPs) in the manufacturing, packaging, labeling, or holding operations for dietary supplements. Even though product registration is not required, these regulations mandate production and quality control standards (including testing for identity, purity and adulterations) for dietary supplements.<ref>U.S. Food and Drug Administration. [https://web.archive.org/web/20021107080706/http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=111 CFR – Code of Federal Regulations Title 21]. Retrieved 16 February 2014.</ref> In the European Union, the [[Food Supplements Directive]] requires that only those supplements that have been proven safe can be sold without a prescription.<ref>{{CELEX|32002L0046|text=Directive 2002/46/EC of the European Parliament and of the Council of 10 June 2002 on the approximation of the laws of the Member States relating to food supplements}}</ref> For most vitamins, [[pharmacopoeia|pharmacopoeial standards]] have been established. In the United States, the [[United States Pharmacopeia]] (USP) sets standards for the most commonly used vitamins and preparations thereof. Likewise, monographs of the [[European Pharmacopoeia]] (Ph.Eur.) regulate aspects of identity and purity for vitamins on the European market.

==Naming==
{| class="wikitable sortable" style="float:right; font-size:90%; margin-left:20px"
|+Nomenclature of reclassified vitamins
|- class="hintergrundfarbe6"
! Previous name
! Chemical name
! Reason for name change<ref name="Bennett" />
|-
| Vitamin B<sub>4</sub>
|[[Adenine]]
| DNA metabolite; synthesized in body
|-
| Vitamin B<sub>8</sub>
|[[Adenylic acid]]
| DNA metabolite; synthesized in body
|-
| Vitamin B<sub>T</sub>
|[[Carnitine]]
| Synthesized in body
|-
| Vitamin F
|[[Essential fatty acid]]s
| Needed in large quantities (does<br /> not fit the definition of a vitamin).
|-
| Vitamin G
|[[Riboflavin]]
| Reclassified as [[B vitamins|Vitamin B<sub>2</sub>]]
|-
| Vitamin H
|[[Biotin]]
| Reclassified as [[B vitamins|Vitamin B<sub>7</sub>]]
|-
| Vitamin J
|[[Catechol]], [[Flavin group|Flavin]]
| Catechol nonessential; flavin (specifically [[riboflavin]]) reclassified<br /> as [[B vitamins|Vitamin B<sub>2</sub>]]
|-
| Vitamin L<sub>1</sub><ref name="VitaminL">Davidson, Michael W. (2004) [http://micro.magnet.fsu.edu/vitamins/pages/anthranilic.html Anthranilic Acid (Vitamin L)] [[Florida State University]]. Retrieved 20-02-07.</ref>
|[[Anthranilic acid]]
| Nonessential
|-
| Vitamin L<sub>2</sub><ref name="VitaminL" />
|[[5′-Methylthioadenosine]]
| RNA metabolite; synthesized in body
|-
| Vitamin M or B<sub>c</sub><ref name=Welch1983>{{cite journal | vauthors = Welch AD | title = Folic acid: discovery and the exciting first decade | journal = Perspectives in Biology and Medicine | volume = 27 | issue = 1 | pages = 64–75 | date = 1983 | pmid = 6359053 | doi = 10.1353/pbm.1983.0006 | s2cid = 31993927 }}</ref>
|[[Folate]]
| Reclassified as [[B vitamins|Vitamin B<sub>9</sub>]]
|-
| Vitamin P
|[[Flavonoids]]
| Many compounds, not proven essential
|-
| Vitamin PP
|[[Niacin (nutrient)|Niacin]]
| Reclassified as [[B vitamins|Vitamin B<sub>3</sub>]]
|-
| Vitamin S
|[[Salicylic acid]]
| Nonessential
|-
| Vitamin U
|[[S-Methylmethionine]]
| Protein metabolite; synthesized in body
|}

The reason that the set of vitamins skips directly from E to K is that the vitamins corresponding to letters F–J were either reclassified over time, discarded as false leads, or renamed because of their relationship to vitamin&nbsp;B, which became a complex of vitamins.

The Danish-speaking scientists who isolated and described vitamin&nbsp;K (in addition to naming it as such) did so because the vitamin is intimately involved in the coagulation of blood following wounding (from the [[Danish language|Danish]] word ''Koagulation''). At the time, most (but not all) of the letters from F through to J were already designated, so the use of the letter K was considered quite reasonable.<ref name="Bennett">{{cite web | vauthors = Bennett D | url = http://www.lifeinyouryears.net/everyvitamin.pdf | title = Every Vitamin Page | work = All Vitamins and Pseudo-Vitamins | access-date = 24 July 2008 | archive-date = 24 October 2019 | archive-url = https://web.archive.org/web/20191024024839/http://www.lifeinyouryears.net/everyvitamin.pdf | url-status = usurped }}</ref><ref name="quiz">{{cite web | url = http://www.pubquizhelp.34sp.com/sci/vitamin.html | archive-url = https://web.archive.org/web/20070704032900/http://www.pubquizhelp.34sp.com/sci/vitamin.html | url-status = dead | archive-date = 4 July 2007 | title = Vitamins and minerals – names and facts | work = pubquizhelp.34sp.com }}</ref> The table ''Nomenclature of reclassified vitamins'' lists chemicals that had previously been classified as vitamins, as well as the earlier names of vitamins that later became part of the B-complex.

The missing numbered  B vitamins were reclassified or determined not to be vitamins. For example, B<sub>9</sub> is [[folic acid]] and five of the folates are in the range B<sub>11</sub> through B<sub>16</sub>. Others, such as [[4-Aminobenzoic acid|PABA]] (formerly B<sub>10</sub>), are biologically inactive, toxic, or with unclassifiable effects in humans, or not generally recognised as vitamins by science,<ref>[http://www.medicalnewstoday.com/articles/195878.php Vitamins: What Vitamins Do I Need?]. Medical News Today. Retrieved on 30 November 2015.</ref> such as the highest-numbered, which some [[naturopath]] practitioners call B<sub>21</sub> and B<sub>22</sub>. There are also lettered B substances (e.g., B<sub>m</sub>) listed at [[B vitamins]] that are not recognized as vitamins. There are other "D vitamins" now recognised as other substances, which some sources of the same type number up to D<sub>7</sub>. The controversial cancer treatment [[laetrile]] was at one point lettered as vitamin B<sub>17</sub>. There appears to be no consensus on the existence of substances that may have at one time been named as vitamins Q, R, T, V, W, X, Y or Z.

"Vitamin N" is a term popularized for the mental health benefits of spending time in nature settings. "Vitamin I" is slang among athletes for frequent/daily consumption of [[ibuprofen]] as a pain-relieving treatment.<ref>{{Cite web |last=Urso |first=Maria |date=2012-10-31 |title=Hope or Hype: Ibuprofen (Vitamin I) |url=https://www.active.com/nutrition/articles/hope-or-hype-ibuprofen-vitamin-i |access-date=2025-06-29 |website=ACTIVE.com |language=en}}</ref>

== See also ==
{{Portal|Food}}
*[[Vitamin deficiency]]
*[[Hypervitaminosis]]
*[[Human nutrition]]

== References ==
{{Reflist|30em}}

== Notes ==
{{notelist}}

== External links ==
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{{EB1922 Poster|Vitamine}}
*[https://www.uthfa.com/wp-content/uploads/2016/08/rda.pdf USDA RDA chart in PDF format] {{Webarchive|url=https://web.archive.org/web/20211109182200/https://www.uthfa.com/wp-content/uploads/2016/08/rda.pdf |date=9 November 2021 }}
*[http://www.hc-sc.gc.ca/fn-an/nutrition/reference/table/ref_vitam_tbl_e.html Health Canada Dietary Reference Intakes Reference Chart for Vitamins]
*[http://dietary-supplements.info.nih.gov/Health_Information/Vitamin_and_Mineral_Supplement_Fact_Sheets.aspx NIH Office of Dietary Supplements: Fact Sheets] {{Webarchive|url=https://web.archive.org/web/20080916005417/http://dietary-supplements.info.nih.gov/Health_Information/Vitamin_and_Mineral_Supplement_Fact_Sheets.aspx |date=16 September 2008 }}
* {{cite web |title=Vitamins and minerals |url=https://www.nhs.uk/conditions/vitamins-and-minerals/ |website=nhs.uk |language=en |date=23 October 2017}}

{{Vitamin}}
{{Food chemistry}}
{{Nutritional pathology}}
{{Dietary supplement}}
{{Authority control}}

[[Category:Vitamins| ]]
[[Category:Essential nutrients]]
[[Category:Nutrition]]