Editing Vegetarianism (section)

==Diet composition and nutrition==
{{Main|Vegetarian nutrition|vegan nutrition}}
Western vegetarian diets are typically high in [[carotenoid]]s, but relatively low in [[omega-3 fatty acid]]s and [[vitamin B12|vitamin B<sub>12</sub>]].<ref name=Key2006>{{cite journal |vauthors=Key TJ, Appleby PN, Rosell MS | title = Health effects of vegetarian and vegan diets | journal = Proceedings of the Nutrition Society | volume = 65 | issue = 1 | pages = 35–41 | year = 2006 | pmid = 16441942 | doi = 10.1079/PNS2005481 | citeseerx = 10.1.1.486.6411 | s2cid = 3796770 }}</ref> Vegans can have particularly low intake of [[vitamin B]] and [[calcium]] if they do not eat enough items such as [[collard greens]], [[Leaf vegetable|leafy greens]], [[tempeh]] and [[tofu]] (soy).<ref>{{Cite journal|last=Craig|first=W. J.|date=2009|title=Health effects of vegan diets|journal=American Journal of Clinical Nutrition|volume=89 | issue = 5 |pages=1627S–33S|doi=10.3945/ajcn.2009.26736n|pmid=19279075|doi-access=free}}</ref> High levels of dietary fiber, [[folic acid]], vitamins C and E, and magnesium, and low consumption of saturated fat are all considered to be beneficial aspects of a vegetarian diet.<ref name=Davey>{{cite journal |vauthors=Davey GK, Spencer EA, Appleby PN, Allen NE, Knox KH, Key TJ | title = EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK | journal = Public Health Nutrition | volume = 6 | issue = 3 | pages = 259–69 | year = 2003 | pmid = 12740075 | doi = 10.1079/PHN2002430 | doi-access = free }}</ref> A well planned vegetarian diet will provide all nutrients in a meat-eater's diet to the same level for all stages of life.<ref>{{cite web |url=http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Vegetarian_and_vegan_eating |title=Vegetarian and vegan eating &#124; Better Health Channel |publisher=Betterhealth.vic.gov.au |access-date=March 31, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150402113541/http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Vegetarian_and_vegan_eating |archive-date=April 2, 2015 }}</ref>

===Protein===
Protein intake in vegetarian diets tends to be lower than in meat diets but can meet the daily requirements for most people.<ref>{{Cite book| last = Peter Emery| first = Tom Sanders| title = Molecular Basis of Human Nutrition| publisher = Taylor & Francis Ltd|year=2002| page = 32| isbn = 978-0-7484-0753-8}}</ref> Studies at [[Harvard University]] as well as other studies conducted in the United States, United Kingdom, Canada, Australia, [[New Zealand]], and various European countries, confirmed that vegetarian diets provide sufficient protein intake as long as a variety of plant sources are available and consumed.<ref>{{Cite book| last = Brenda Davis| first = Vesanto Melina| title = The New Becoming Vegetarian| publisher = Book Publishing Company|year=2003| pages = 57–58| isbn = 978-1-57067-144-9}}</ref>

===Iron===
Vegetarian diets typically contain similar levels of iron to non-vegetarian diets, but this has lower [[bioavailability]] than iron from meat sources, and its absorption can sometimes be inhibited by other dietary constituents.<ref>{{cite web |url=http://www.vegsoc.org/page.aspx?pid=782 |title=Vegetarian Society - Factsheet - Iron |publisher=Vegsoc.org |date=September 22, 2014 |access-date=March 31, 2015 |archive-url=https://web.archive.org/web/20130429230632/http://www.vegsoc.org/page.aspx?pid=782 |archive-date=April 29, 2013 |url-status=dead }}</ref> According to the Vegetarian Resource Group, consuming food that contains vitamin C, such as citrus fruit or juices, tomatoes, or broccoli, is a good way to increase the amount of iron absorbed at a meal.<ref>{{cite web |url=http://www.vrg.org/nutshell/nutshell.htm#iron |title=Vegetarianism in a Nutshell |publisher=Vrg.org |access-date=March 31, 2015 |archive-date=June 26, 2015 |archive-url=https://web.archive.org/web/20150626122237/http://www.vrg.org/nutshell/nutshell.htm#iron |url-status=live }}</ref> Vegetarian foods rich in iron include [[black turtle bean|black beans]], [[cashew]]s, [[hempseed]], [[kidney bean]]s, [[broccoli]], [[lentil]]s, [[oatmeal]], [[raisin]]s, [[jaggery]], [[spinach]], [[cabbage]], lettuce, [[black-eyed pea]]s, [[soybean]]s, many [[breakfast cereal]]s, [[sunflower seed]]s, [[chickpea]]s, [[tomato juice]], [[tempeh]], [[molasses]], [[thyme]], and [[whole-wheat bread]].<ref>{{cite web |url=http://goveg.com/essential_nutrients.asp#iron |title=// Health Issues // Optimal Vegan Nutrition |publisher=Goveg.com |access-date=August 9, 2009 |archive-date=April 4, 2009 |archive-url=https://web.archive.org/web/20090404064615/http://www.goveg.com/essential_nutrients.asp#iron |url-status=live }}</ref>{{Failed verification|date=January 2023}} The related vegan diets can often be higher in iron than vegetarian diets, because dairy products are low in iron.<ref name=Davey/> Iron stores often tend to be lower in vegetarians than non-vegetarians, and a few small studies report very high rates of iron deficiency (up to 40%,<ref>{{cite journal | vauthors = Waldmann A, Koschizke JW, Leitzmann C, Hahn A | title = Dietary Iron Intake and Iron Status of German Female Vegans: Results of the German Vegan Study | journal = Ann Nutr Metab | volume = 48 | issue = 2 | pages = 103–108 | year = 2004 | pmid = 14988640 | doi = 10.1159/000077045 | s2cid = 21370991 | url = http://www.repo.uni-hannover.de/handle/123456789/2754 | access-date = September 3, 2018 | archive-date = November 16, 2018 | archive-url = https://web.archive.org/web/20181116213523/https://www.repo.uni-hannover.de/handle/123456789/2754 | url-status = live }}</ref> and 58%<ref>{{cite journal |vauthors=Krajcovicová-Kudlácková M, Simoncic R, Béderová A, Grancicová E, Magálová T | title = Influence of vegetarian and mixed nutrition on selected haematological and biochemical parameters in children | journal = Nahrung | volume = 41 | issue = 5 | pages = 311–14 | year = 1997 | pmid = 9399258 | doi = 10.1002/food.19970410513 }}</ref> of the respective vegetarian or vegan groups). However, the [[American Dietetic Association]] states that iron deficiency is no more common in vegetarians than non-vegetarians (adult males are rarely iron deficient); iron deficiency [[Anemia|anaemia]] is rare no matter the diet.<ref>{{cite journal | vauthors = Craig WJ, Mangels AR | title = Position of the American Dietetic Association: vegetarian diets | journal = Journal of the American Dietetic Association | volume = 109 | issue = 7 | pages = 1266–82 | year = 2009 | pmid = 19562864 | doi = 10.1016/j.jada.2009.05.027 | s2cid = 7906168 | url = https://digitalcommons.andrews.edu/pubs/1954 | access-date = May 23, 2021 | archive-date = April 19, 2021 | archive-url = https://web.archive.org/web/20210419062508/https://digitalcommons.andrews.edu/pubs/1954/ | url-status = live }}</ref>

===Vitamin B<sub>12</sub>===
[[Vitamin B12|Vitamin B<sub>12</sub>]] is not generally present in plants but is naturally found in foods of animal origin.<ref name="lpi">{{cite web|date=June 4, 2015|title=Vitamin B12|publisher=Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis, OR|url=https://lpi.oregonstate.edu/mic/vitamins/vitamin-B12|access-date=April 30, 2019|archive-date=November 17, 2021|archive-url=https://web.archive.org/web/20211117190259/https://lpi.oregonstate.edu/mic/vitamins/vitamin-B12|url-status=live}}</ref><ref name="ODS_B12">{{cite web |url=http://ods.od.nih.gov/factsheets/vitaminb12.asp |title=Dietary Supplement Fact Sheet: Vitamin B<sub>12</sub> |access-date=November 13, 2009 |publisher=US National Institutes of Health: Office of Dietary Supplements |archive-date=November 25, 2009 |archive-url=https://web.archive.org/web/20091125222656/http://ods.od.nih.gov/factsheets/vitaminB12.asp |url-status=live }}</ref> [[Lacto-ovo vegetarianism|Lacto-ovo vegetarians]] can obtain B<sub>12</sub> from [[dairy product]]s and eggs, and vegans can obtain it from manufactured [[Food fortification|fortified food]]s (including [[plant-based diet|plant-based]] products and [[breakfast cereal]]s) and dietary supplements.<ref name=lpi/><ref name="Vegan Society B12 factsheet">{{cite web|title=What Every Vegan Should Know About Vitamin B12|publisher=Vegan Society|date=October 31, 2001|url=http://www.vegansociety.com/lifestyle/nutrition/b12.aspx|access-date=October 27, 2010|archive-date=December 20, 2010|archive-url=https://web.archive.org/web/20101220140454/http://www.vegansociety.com/lifestyle/nutrition/b12.aspx|url-status=live}}</ref><ref>{{cite web |url=https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/ |title=Vitamins and minerals - B vitamins and folic acid |publisher=UK National Health Service |date=March 3, 2017 |access-date=April 30, 2019 |archive-date=January 21, 2021 |archive-url=https://web.archive.org/web/20210121090421/https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/ |url-status=live }}</ref> A strict vegan diet avoiding consumption of all animal products risks vitamin B<sub>12</sub> deficiency, which can lead to [[hyperhomocysteinemia]], a risk factor for several health disorders, including [[anemia]], [[neurological deficit]]s, [[gastrointestinal]] problems, [[platelet]] disorders, and increased risk for [[cardiovascular diseases]].<ref name=lpi/><ref name="Obersby">{{cite journal|last1=Obersby|first1=Derek|last2=Chappell|first2=David C.|last3=Dunnett|first3=Andrew|last4=Tsiami|first4=Amalia A.|date=January 8, 2013|title=Plasma total homocysteine status of vegetarians compared with omnivores: a systematic review and meta-analysis|journal=British Journal of Nutrition|volume=109|issue=5|pages=785–794|doi=10.1017/s000711451200520x|issn=0007-1145|pmid=23298782|doi-access=free|url=https://repository.uwl.ac.uk/id/eprint/928/1/Plasma%20total%20homocysteine%20status%20of%20vegetarians%20compared%20with%20omnivores.pdf|access-date=March 18, 2020|archive-date=October 25, 2020|archive-url=https://web.archive.org/web/20201025103512/https://repository.uwl.ac.uk/id/eprint/928/1/Plasma%20total%20homocysteine%20status%20of%20vegetarians%20compared%20with%20omnivores.pdf|url-status=live}}</ref> The [[Dietary Reference Intake|recommended daily dietary intake]] of B<sub>12</sub> in the United States and Canada is 0.4 [[microgram|mcg]] (ages 0–6 months), rising to 1.8 mcg (9–13 years), 2.4 mcg (14+ years), and 2.8 mcg (lactating female).<ref name="ODS_B12"/> While the body's daily requirement for vitamin B<sub>12</sub> is in [[microgram]] amounts, deficiency of the vitamin through strict practice of a vegetarian diet without supplementation can increase the risk of several chronic diseases.<ref name=lpi/><ref name=Obersby/><ref name="ODS_B12"/>

===Fatty acids===
Plant-based, or vegetarian, sources of [[Omega 3]] fatty acids include [[soy]], [[walnut]]s, pumpkin seeds, [[canola oil]], [[kiwifruit]], [[hempseed]], [[algae]], [[chia seed]], [[flaxseed]], echium seed and [[Leaf vegetable|leafy vegetables]] such as lettuce, [[spinach]], [[cabbage]] and [[portulaca oleracea|purslane]]. Purslane contains more Omega 3 than any other known leafy green. [[Olive]]s (and [[olive oil]]) are another important plant source of unsaturated fatty acids. Plant foods can provide [[alpha-linolenic acid]] which the human body uses to synthesize the long-chain n-3 fatty acids [[Eicosapentaenoic acid|EPA]] and [[Docosahexaenoic acid|DHA]]. EPA and DHA can be obtained directly in high amounts from oily fish, fish oil, or algae oil. Vegetarians, and particularly vegans, have lower levels of EPA and DHA than meat-eaters. While the health effects of low levels of EPA and DHA are unknown, it is unlikely that supplementation with alpha-linolenic acid will significantly increase levels.<ref>{{cite journal |vauthors=Rosell MS, Lloyd-Wright Z, Appleby PN, Sanders TA, Allen NE, Key TJ | title = Long-chain n-3 polyunsaturated fatty acids in plasma in British meat-eating, vegetarian, and vegan men | journal = Am J Clin Nutr | volume = 82 | issue = 2 | pages = 327–34 | year = 2003 | pmid = 16087975 | doi = 10.1093/ajcn.82.2.327 | doi-access = free }}</ref>{{Clarify|date=May 2011}}. Significantly, for vegetarians, certain [[algae]] such as [[spirulina (dietary supplement)|spirulina]] are good sources of [[gamma-linolenic acid]] (GLA), [[alpha-linolenic acid]] (ALA), [[linoleic acid]] (LA), [[stearidonic acid]] (SDA), [[eicosapentaenoic acid]] (EPA), [[docosahexaenoic acid]] (DHA), and [[arachidonic acid]] (AA).<ref name="uzbek">{{cite journal |author1=Babadzhanov A |author2=Abdusamatova N |author3=Yusupova F |author4=Faizullaeva N |author5=Mezhlumyan LG |author6=Malikova MKh | title = Chemical Composition of Spirulina platensis Cultivated in Uzbekistan | journal = Chemistry of Natural Compounds | volume = 40 | issue = 3 | pages = 276–279 | year = 2004 | doi = 10.1023/B:CONC.0000039141.98247.e8|bibcode=2004CNatC..40..276B |s2cid=23130198 }}</ref><ref name="biomass">{{cite journal |vauthors=Tokuşoglu Ö, Uunal MK | title = Biomass Nutrient Profiles of Three Microalgae: Spirulina platensis, Chlorella vulgaris, and Isochrisis galena | journal=Journal of Food Science | volume = 68 | issue = 4 | pages = 1144–1148 | year = 2003 | doi = 10.1111/j.1365-2621.2003.tb09615.x }}</ref>

===Calcium===
[[Calcium]] intake in vegetarians and vegans can be similar to non-vegetarians, as long as the diet is properly planned.<ref name="Academy of Nutrition and Dietetics">{{cite web|title=Meeting Calcium Recommendations on a Vegan Diet|url=http://vegetariannutrition.net/docs/Calcium-Vegetarian-Nutrition.pdf|publisher=Academy of Nutrition and Dietetics|access-date=April 29, 2014|archive-date=April 29, 2014|archive-url=https://web.archive.org/web/20140429045652/http://vegetariannutrition.net/docs/Calcium-Vegetarian-Nutrition.pdf|url-status=live}}</ref> Lacto-ovo vegetarians that include dairy products can still obtain calcium from dairy sources like milk, yogurt, and cheese.<ref name="Calcium Fact Sheet">{{cite web|title=Calcium Fact Sheet|url=http://ods.od.nih.gov/factsheets/Calcium-HealthProfessional|access-date=April 29, 2014|archive-date=April 29, 2014|archive-url=https://web.archive.org/web/20140429075612/http://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/|url-status=live}}</ref>

Non-dairy milks that are fortified with calcium, such as soymilk and [[almond milk]] can also contribute a significant amount of calcium in the diet.<ref name="Mangels">{{cite web|last=Mangels|first=Reed|title=Calcium in the Vegan Diet|url=http://www.vrg.org/nutrition/calcium.php|access-date=April 29, 2014|archive-date=May 30, 2014|archive-url=https://web.archive.org/web/20140530003649/http://www.vrg.org/nutrition/calcium.php|url-status=live}}</ref> [[Broccoli]], [[Chinese cabbage|bok choy]], and [[kale]] have also been found to have calcium that is well absorbed in the body.<ref name="Academy of Nutrition and Dietetics"/><ref name="Calcium Fact Sheet"/><ref name="Overview of Calcium">{{cite report|author=((Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium))|veditors=Ross AC, Taylor CL, Yaktine AL, et al.|title=Dietary Reference Intakes for Calcium and Vitamin D|series=Vol. 2, Overview of Calcium|place=Washington, DC|publisher=National Academies Press|year=2011|url=https://www.ncbi.nlm.nih.gov/books/NBK56060/?report=reader|access-date=April 29, 2014|archive-date=September 4, 2015|archive-url=https://web.archive.org/web/20150904031151/http://www.ncbi.nlm.nih.gov/books/NBK56060/?report=reader|url-status=live}}</ref> Though the calcium content per serving is lower in these vegetables than a glass of milk, the absorption of the calcium into the body is higher.<ref name="Calcium Fact Sheet"/><ref name="Overview of Calcium"/> Other foods that contain calcium include calcium-set tofu, blackstrap molasses, [[Turnip|turnip greens]], mustard greens, soybeans, tempeh, almonds, okra, dried figs, and [[tahini]].<ref name="Academy of Nutrition and Dietetics"/><ref name="Mangels"/> Though calcium can be found in [[Spinach]], [[swiss chard]], [[bean]]s and [[Beet|beet greens]], they are generally not considered to be a good source since the calcium binds to oxalic acid and is poorly absorbed into the body.<ref name="Calcium Fact Sheet"/> Phytic acid found in nuts, seeds, and beans may also impact calcium absorption rates.<ref name="Calcium Fact Sheet"/> See the National Institutes of Health Office of Dietary Supplements for calcium needs for various ages,<ref name="Calcium Fact Sheet"/> the Vegetarian Resource Group<ref name="Mangels"/> and the Vegetarian Nutrition Calcium Fact Sheet from the Academy of Nutrition and Dietetics<ref name="Academy of Nutrition and Dietetics"/> for more specifics on how to obtain adequate calcium intake on a vegetarian or vegan diet.

===Vitamin D===
{{Further|Vitamin D}}
Vitamin D needs can be met via the human body's own generation upon sufficient and sensible exposure to ultraviolet (UV) light in sunlight.<ref>{{cite web|title=Vitamin D is Synthesized From Cholesterol and Found in Cholesterol-Rich Foods|url=http://www.cholesterol-and-health.com/Vitamin-D.html|publisher=Cholesterol and Health|access-date=February 10, 2013|archive-url=https://web.archive.org/web/20160817204329/http://www.cholesterol-and-health.com/Vitamin-D.html|archive-date=August 17, 2016|url-status=dead}}</ref><ref>{{cite journal |vauthors=Crissey SD, Ange KD, Jacobsen KL, Slifka KA, Bowen PE, Stacewicz-Sapuntzakis M, Langman CB, Sadler W, Kahn S, Ward A | title = Serum concentrations of lipids, vitamin D metabolites, retinol, retinyl esters, tocopherols and selected carotenoids in twelve captive wild felid species at four zoos | journal = The Journal of Nutrition | volume = 133 | issue = 1 | pages = 160–6 | year = 2003 | pmid = 12514284 | doi = 10.1093/jn/133.1.160 | doi-access = free }}</ref> Products including milk, [[soy milk]] and [[cereal grain]]s may be [[Food fortification|fortified]] to provide a source of vitamin D.<ref>{{cite web|url=http://dietary-supplements.info.nih.gov/factsheets/vitamind.asp|title=Dietary Supplement Fact Sheet: Vitamin D|publisher=National Institutes of Health|access-date=September 10, 2007|archive-url=https://web.archive.org/web/20070716065832/http://dietary-supplements.info.nih.gov/factsheets/vitamind.asp |url-status=dead|archive-date=July 16, 2007}}</ref> For those who do not get adequate sun exposure or food sources, vitamin D supplementation may be necessary.

====Vitamin D<sub>2</sub>====
* [[Plants]]
** [[Alfalfa]] (''Medicago sativa subsp. sativa''), shoot: 4.8 μg (192 IU) vitamin D<sub>2</sub>, 0.1 μg (4 IU) vitamin D<sub>3</sub><ref>{{cite web|url=http://sun.ars-grin.gov:8080/npgspub/xsql/duke/plantdisp.xsql?taxon=606|title=Dr. Duke's Phytochemical and Ethnobotanical Databases|publisher=Sun.ars-grin.gov|access-date=March 31, 2015|url-status=dead|archive-url=https://web.archive.org/web/20151016051622/http://sun.ars-grin.gov:8080/npgspub/xsql/duke/plantdisp.xsql?taxon=606|archive-date=October 16, 2015}}</ref>
* [[Fungus]], from USDA nutrient database,<ref>{{cite web |url=http://www.nal.usda.gov/fnic/foodcomp/search/index.html |title=USDA nutrient database&nbsp;– ''use the keyword 'portabella' and then click submit'' |access-date=March 9, 2012 |archive-date=February 22, 2015 |archive-url=https://web.archive.org/web/20150222164135/http://www.nal.usda.gov/fnic/foodcomp/search/index.html |url-status=dead }}</ref> per 100 g:
** Mushrooms, portabella, exposed to [[ultraviolet light]], raw: Vitamin D<sub>2</sub>: 11.2 μg (446 IU)
** Mushrooms, portabella, exposed to ultraviolet light, grilled: Vitamin D<sub>2</sub>: 13.1 μg (524 IU)
** Mushrooms, shiitake, dried: Vitamin D<sub>2</sub>: 3.9 μg (154 IU)
** Mushrooms, shiitake, raw: Vitamin D<sub>2</sub>: 0.4 μg (18 IU)
** Mushrooms, portabella, raw: Vitamin D<sub>2</sub>: 0.3 μg (10 IU)
** Mushroom powder, any species, illuminated with sunlight or artificial ultraviolet light sources

Vitamin D<sub>2</sub>, or [[ergocalciferol]] is found in fungus (except [[alfalfa]] which is a [[plantae]]) and created from [[viosterol]], which in turn is created when ultraviolet light activates [[ergosterol]] (which is found in fungi and named as a [[sterol]] from [[ergot]]). Any [[Ultraviolet light|UV]]-irradiated fungus including [[yeast]] form vitamin D<sub>2</sub>.<ref name=Bowerman>{{cite news |url=https://www.latimes.com/archives/la-xpm-2008-mar-31-he-eat31-story.html |title=If mushrooms see the light |work=Los Angeles Times |date=March 31, 2008 |access-date=March 25, 2010 |first=Susan |last=Bowerman |archive-date=September 4, 2011 |archive-url=https://web.archive.org/web/20110904135924/http://articles.latimes.com/2008/mar/31/health/he-eat31 |url-status=live }}</ref> Human bioavailability of vitamin D<sub>2</sub> from vitamin D<sub>2</sub>-enhanced button mushrooms via UV-B irradiation is effective in improving vitamin D status and not different from a vitamin D<sub>2</sub> supplement according to study.<ref>{{cite journal|title=Bioavailability of vitamin D2 from UV-B-irradiated button mushrooms in healthy adults deficient in serum 25-hydroxyvitamin D: a randomized controlled trial|journal=European Journal of Clinical Nutrition|date=May 4, 2011|author1=P Urbain|author2=F Singler|author3=G Ihorst|author4=H-K Biesalski|author5=H Bertz|issue=8|pages= 965–971|doi= 10.1038/ejcn.2011.53|volume=65|pmid=21540874|doi-access=free}}</ref> For example, vitamin D<sub>2</sub> from UV-irradiated yeast baked into bread is bioavailable.<ref>{{cite journal|title=Bioavailability and Efficacy of Vitamin D 2 from UV-Irradiated Yeast in Growing, Vitamin D-Deficient Rats |date=May 24, 2012 |pmid=21332187 |doi=10.1021/jf104679c |volume=59 |issue=6 |pmc=3235799 |vauthors=Hohman EE, Martin BR, Lachcik PJ, Gordon DT, Fleet JC, Weaver CM |journal=J. Agric. Food Chem. |pages=2341–6}}</ref>
By visual assessment or using a chromometer, no significant discoloration of irradiated mushrooms, as measured by the degree of "whiteness", was observed<ref>{{cite journal |vauthors=Koyyalamudi SR, Jeong SC, Song CH, Cho KY, Pang G | title = Vitamin D<sub>2</sub> formation and bioavailability from Agaricus bisporus button mushrooms treated with ultraviolet irradiation | journal = Journal of Agricultural and Food Chemistry | volume = 57 | issue = 8 | pages = 3351–5 | year = 2009 | pmid = 19281276 | doi = 10.1021/jf803908q | bibcode = 2009JAFC...57.3351K }}</ref> making it hard to discover if they have been treated without labeling. Claims have been made that a normal serving (approx. 3 oz or 1/2 cup, or 60 grams) of mushrooms treated with ultraviolet light increase their vitamin D content to levels up to 80 micrograms,<ref>{{cite web |author=Using Fresh Mushrooms as a Source of Vitamin D |url=http://www.fitday.com/fitness-articles/nutrition/healthy-eating/using-fresh-mushrooms-as-a-source-of-vitamin-d.html |title=Using Fresh Mushrooms as a Source of Vitamin D / Nutrition / Healthy Eating |publisher=Fitday.com |access-date=September 12, 2012 |archive-date=September 23, 2012 |archive-url=https://web.archive.org/web/20120923065357/http://www.fitday.com/fitness-articles/nutrition/healthy-eating/using-fresh-mushrooms-as-a-source-of-vitamin-d.html |url-status=live }}</ref> or 2700 IU if exposed to just 5 minutes of UV light after being harvested.<ref>{{Cite news|title =Bringing Mushrooms Out of the Dark|date =April 18, 2006|url =http://www.msnbc.msn.com/id/12370708|work =MSNBC|access-date =August 6, 2007|archive-date =November 1, 2007|archive-url =https://web.archive.org/web/20071101072649/http://www.msnbc.msn.com/id/12370708|url-status =dead}}</ref>

===Choline===
{{Main|Choline}}
[[Choline]] is a nutrient that helps transfer signals between nerve cells and is involved in liver function. It is highest in dairy foods and meat but it is possible to be obtained through a vegan diet.<ref>{{Cite news|last=Parkinson|first=Caroline|date=August 30, 2019|title=The brain nutrient vegans need to know about|website=BBC News|url=https://www.bbc.com/news/health-49509504|access-date=April 27, 2020|archive-date=May 21, 2020|archive-url=https://web.archive.org/web/20200521124416/https://www.bbc.com/news/health-49509504|url-status=live}}</ref>