维生素B₃

維生素B₃
維生素B3
藥物種類
	維生素B3的三個維生素異構體之一——煙酰胺的結構
生物靶標	酶輔因子
ATC代碼	A11H
外部連結
MeSH	D009536
AHFS/Drugs.com	Niacin

維生素B₃屬於維生素B族，包括三個維生素異構體（英語：vitamer），分別是煙酸、煙酰胺和煙酰胺核糖。^[1]這三種維生素異構體在人體內都會轉化成煙酰胺腺嘌呤二核苷酸（NAD）。^[1]生命需要NAD，而人體不能在沒有維生素B₃或色氨酸的情況下合成NAD。^[1]煙酰胺核糖於2004年被確認是維生素B₃之一。^[2]^[1]

動植物可以通過色氨酸合成煙酸。^[3]煙酸存在於許多食物中，其中肉類、家禽、金槍魚和三文魚中的煙酸含量最高，而堅果、豆類和種子中的煙酸含量較少。^[4]^[5]作為營養補充品的煙酸可以治療因缺乏維生素B₃導致的糙皮病。糙皮病的症狀有皮膚和口腔病變、貧血、頭痛和疲倦。^[6]許多國家都會要求在麵粉和其它糧食添加煙酸防止糙皮病。^[4]^[7]

煙酰胺是輔因子煙酰胺腺嘌呤二核苷酸（NAD）和煙酰胺腺嘌呤二核苷酸磷酸（NADP⁺）的組成部分。雖然煙酸和煙酰胺在維生素活性上相同，但作為酰胺的煙酰胺不會還原膽固醇，也不會造成臉紅（英語：flushing (physiology)）。^[8]^[9]由於臉紅被認為是不良反應，因此煙酰胺被推薦為維生素B₃缺乏症的治療方法。^[10]

參考資料

^ ^1.0 ^1.1 ^1.2 ^1.3 Stipanuk, Martha H.; Caudill, Marie A. Biochemical, Physiological, and Molecular Aspects of Human Nutrition - E-Book. Elsevier Health Sciences. 2013: 541. ISBN 9780323266956 （英語）. Vitamin B3... potentially includes three different molecular forms: nicotinic acid, niacinamide, and nicotinamide riboside
^ Bieganowski, P; Brenner, C. Discoveries of nicotinamide riboside as a nutrient and conserved NRK genes establish a Preiss-Handler independent route to NAD+ in fungi and humans.. Cell. 14 May 2004, 117 (4): 495–502. PMID 15137942. doi:10.1016/s0092-8674(04)00416-7 .
^ Institute of Medicine. Niacin. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: The National Academies Press. 1998: 123–149 [29 August 2018]. ISBN 9780309065542. （原始內容存檔於2018-09-01）.
^ ^4.0 ^4.1 Niacin. Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis, OR. 8 October 2018 [16 September 2019]. （原始內容存檔於2019-09-12）.
^ Niacin Fact Sheet for Health Professionals. Office of Dietary Supplements, US National Institutes of Health. 3 June 2020 [29 June 2020]. （原始內容存檔於2020-06-23）.
^ Hegyi J, Schwartz RA, Hegyi V. Pellagra: dermatitis, dementia, and diarrhea. International Journal of Dermatology. January 2004, 43 (1): 1–5. PMID 14693013. S2CID 33877664. doi:10.1111/j.1365-4632.2004.01959.x.
^ Why fortify?. Food Fortification Initiative. 2017 [4 April 2017]. （原始內容存檔於4 April 2017）.
^ Jaconello P. Niacin versus niacinamide. CMAJ. October 1992, 147 (7): 990. PMC 1336277 . PMID 1393911.
^ Kirkland JB. Niacin requirements for genomic stability. Mutation Research. May 2012, 733 (1–2): 14–20 [2023-01-29]. PMID 22138132. doi:10.1016/j.mrfmmm.2011.11.008. （原始內容存檔於2020-08-04）.
^ World Health Organization. Pellagra And Its Prevention And Control In Major Emergencies (報告). World Health Organization (WHO). 2000. hdl:10665/66704 . WHO/NHD/00.10.

[Sti2013-1] 1.0 ^1.1 ^1.2 ^1.3 Stipanuk, Martha H.; Caudill, Marie A. Biochemical, Physiological, and Molecular Aspects of Human Nutrition - E-Book. Elsevier Health Sciences. 2013: 541. ISBN 9780323266956 （英語）. Vitamin B3... potentially includes three different molecular forms: nicotinic acid, niacinamide, and nicotinamide riboside

[Bieganowski_&_Brenner,_Cell_2004:_discovery_of_NR_as_an_NAD_precursor-2] Bieganowski, P; Brenner, C. Discoveries of nicotinamide riboside as a nutrient and conserved NRK genes establish a Preiss-Handler independent route to NAD+ in fungi and humans.. Cell. 14 May 2004, 117 (4): 495–502. PMID 15137942. doi:10.1016/s0092-8674(04)00416-7 .

[DRItext-3] Institute of Medicine. Niacin. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: The National Academies Press. 1998: 123–149 [29 August 2018]. ISBN 9780309065542. （原始內容存檔於2018-09-01）.

[lpi-4] 4.0 ^4.1 Niacin. Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis, OR. 8 October 2018 [16 September 2019]. （原始內容存檔於2019-09-12）.

[NIH_Fact_Sheet-5] Niacin Fact Sheet for Health Professionals. Office of Dietary Supplements, US National Institutes of Health. 3 June 2020 [29 June 2020]. （原始內容存檔於2020-06-23）.

[Hegyi2004-6] Hegyi J, Schwartz RA, Hegyi V. Pellagra: dermatitis, dementia, and diarrhea. International Journal of Dermatology. January 2004, 43 (1): 1–5. PMID 14693013. S2CID 33877664. doi:10.1111/j.1365-4632.2004.01959.x.

[WhyFortify-7] Why fortify?. Food Fortification Initiative. 2017 [4 April 2017]. （原始內容存檔於4 April 2017）.

[8] Jaconello P. Niacin versus niacinamide. CMAJ. October 1992, 147 (7): 990. PMC 1336277 . PMID 1393911.

[pmid22138132-9] Kirkland JB. Niacin requirements for genomic stability. Mutation Research. May 2012, 733 (1–2): 14–20 [2023-01-29]. PMID 22138132. doi:10.1016/j.mrfmmm.2011.11.008. （原始內容存檔於2020-08-04）.

[Pellagra_And_Its_Prevention-10] World Health Organization. Pellagra And Its Prevention And Control In Major Emergencies (報告). World Health Organization (WHO). 2000. hdl:10665/66704 . WHO/NHD/00.10.

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