Difference between revisions of "Niacin" - New World Encyclopedia
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| align="center" colspan="2" bgcolor="#ffffff" | [[Image:Niacin structure.png|120px|Niacin]] | | align="center" colspan="2" bgcolor="#ffffff" | [[Image:Niacin structure.png|120px|Niacin]] | ||
|- | |- | ||
| − | | [[IUPAC nomenclature|Systematic name]] | + | | [[IUPAC nomenclature|Systematic name]]* |
| 3-Pyridinecarboxylic acid | | 3-Pyridinecarboxylic acid | ||
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| Niacin<br>Pyridine-β-carboxylic acid<br>Vitamin B<sub>3</sub> | | Niacin<br>Pyridine-β-carboxylic acid<br>Vitamin B<sub>3</sub> | ||
|- | |- | ||
| − | | [[Chemical formula]] | + | | [[Chemical formula]]* |
| C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub> | | C<sub>6</sub>H<sub>5</sub>NO<sub>2</sub> | ||
|- | |- | ||
| − | | [[Molecular mass]] | + | | [[Molecular mass]]* |
| 123.11 g/mol | | 123.11 g/mol | ||
|- | |- | ||
| − | | [[Melting point]] | + | | [[Melting point]]* |
| 236.6 °C | | 236.6 °C | ||
|- | |- | ||
| − | | [[Boiling point]] | + | | [[Boiling point]]* |
| decomposes | | decomposes | ||
|- | |- | ||
| − | | [[CAS registry number|CAS number]] | + | | [[CAS registry number|CAS number]]* |
| [59-67-6] | | [59-67-6] | ||
|- | |- | ||
| − | | [[Simplified molecular input line entry specification|SMILES]] | + | | [[Simplified molecular input line entry specification|SMILES]]* |
| OC(C1=CN=CC=C1)=O | | OC(C1=CN=CC=C1)=O | ||
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| − | '''Niacin''', also known as '''nicotinic acid''' or '''vitamin B<sub>3</sub>''', is a water- | + | '''Niacin''', also known as '''nicotinic acid''' or '''vitamin B<sub>3</sub>''', is one of the B vitamins (or vitamin B complex), a group of chemically distinct, water-soluable vitamins that also includes [[thiamine]], [[riboflaven]], pantothenic acid, biotin, pyridoxine, folic acid, and others. Once considered to be a single vitamin, vitamin B is now seen as a complex of different vitamins that generally are found in the same foods. Vitamins are organic ([[carbon]]-containing) nutrients obtained through the diet and essential in small amounts for normal [[metabolism|metabolic]] reactions. |
| − | The designation ''vitamin B<sub>3</sub>'' also includes the corresponding [[amide]] [[nicotinamide]], or '''niacinamide''', whose chemical formula is C<sub>6</sub>H<sub>6</sub>N<sub>2</sub>O | + | Niacin is a vitamin whose derivatives, such as [[Nicotinamide adenine dinucleotide|NADH]], NAD, NAD<sup>+</sup>, and NADP, play essential roles in energy metabolism in the living [[cell (biology)|cell]] and [[DNA]] repair (Feinburg 2006). The designation ''vitamin B<sub>3</sub>'', whose chemical formula is C<sub>5</sub>H<sub>4</sub>NCOOH (or alternatively, C<sub>6</sub>H<sub>6</sub>NO<sub>2</sub>), also includes the corresponding [[amide]] [[nicotinamide]], or '''niacinamide''', whose chemical formula is C<sub>6</sub>H<sub>6</sub>N<sub>2</sub>O. |
| − | |||
| − | |||
| + | Niacin deficiency results in pellagra. | ||
==Deficiency and Overdose== | ==Deficiency and Overdose== | ||
[[Image:nicotinamide.png|thumb|80px|right|Chemical structure of nicotinamide.]] | [[Image:nicotinamide.png|thumb|80px|right|Chemical structure of nicotinamide.]] | ||
| − | Severe lack of niacin causes the deficiency disease [[pellagra]], whereas a mild deficiency slows down the [[metabolism]] decreasing [[temperature|cold]] tolerance. Extemely high doses of niacin can cause [[niacin maculopathy]], a thickening of the [[macula]] and [[retina]] which leads to blurred vision and blindness. <ref>JD Gass, <i>Nictonic Acid Maculopathy</I>, Am. J. Opthamology, 1973;76:500-10</ref> The recommended daily allowance of niacin is 2-12 mg a day for children, 14 mg a day for women, 16 mg a day for men, and 18 mg a day for pregnant or breast-feeding women.<ref>{{pauling|id=vitamins/niacin|title=Niacin|author=Jane Higdon}}</ref> Over 20 mg per day may produce hot flushes lasting 15-30 minutes in duration. | + | Severe lack of niacin causes the deficiency [[disease]] [[pellagra]], whereas a mild deficiency slows down the [[metabolism]] decreasing [[temperature|cold]] tolerance. The symptoms of pellagra include high sensitivity to sunlight, aggression, dermatitis, red skin lesions, insomnia, weakness, mental confusion, diarrhea, and dementia (eventually). Overall, the main results of pellagra can easily be remembered as "the four D's": diarrhea, dermatitis, dementia, and death. Untreated, the disease can kill within four or five years. |
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| + | Extemely high doses of niacin can cause [[niacin maculopathy]], a thickening of the [[macula]] and [[retina]] which leads to blurred vision and blindness. <ref>JD Gass, <i>Nictonic Acid Maculopathy</I>, Am. J. Opthamology, 1973;76:500-10</ref> The recommended daily allowance of niacin is 2-12 mg a day for children, 14 mg a day for women, 16 mg a day for men, and 18 mg a day for pregnant or breast-feeding women.<ref>{{pauling|id=vitamins/niacin|title=Niacin|author=Jane Higdon}}</ref> Over 20 mg per day may produce hot flushes lasting 15-30 minutes in duration. | ||
==Discovery== | ==Discovery== | ||
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==References== | ==References== | ||
<div class="references-small"><references/></div> | <div class="references-small"><references/></div> | ||
| + | |||
| + | * Feinberg School, Norwthwestern University. 2006. [http://www.feinberg.northwestern.edu/nutrition/factsheets/vitamin-b3.html Nutrition Fact Sheet: Niacin (vitamin B3)]. ''NorthwesternNutrition. Retrieved January 28, 2007. | ||
==External links== | ==External links== | ||
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[[Category:Life sciences]] | [[Category:Life sciences]] | ||
| − | {{ | + | {{credit2|Niacin|103484979|Pellagra|102708804}} |
Revision as of 01:58, 29 January 2007
| Niacin[1] | |
|---|---|
| |
| Systematic name | 3-Pyridinecarboxylic acid |
| Other names | Niacin Pyridine-β-carboxylic acid Vitamin B3 |
| Chemical formula | C6H5NO2 |
| Molecular mass | 123.11 g/mol |
| Melting point | 236.6 °C |
| Boiling point | decomposes |
| CAS number | [59-67-6] |
| SMILES | OC(C1=CN=CC=C1)=O |
| Disclaimer and references | |
Niacin, also known as nicotinic acid or vitamin B3, is one of the B vitamins (or vitamin B complex), a group of chemically distinct, water-soluable vitamins that also includes thiamine, riboflaven, pantothenic acid, biotin, pyridoxine, folic acid, and others. Once considered to be a single vitamin, vitamin B is now seen as a complex of different vitamins that generally are found in the same foods. Vitamins are organic (carbon-containing) nutrients obtained through the diet and essential in small amounts for normal metabolic reactions.
Niacin is a vitamin whose derivatives, such as NADH, NAD, NAD+, and NADP, play essential roles in energy metabolism in the living cell and DNA repair (Feinburg 2006). The designation vitamin B3, whose chemical formula is C5H4NCOOH (or alternatively, C6H6NO2), also includes the corresponding amide nicotinamide, or niacinamide, whose chemical formula is C6H6N2O.
Niacin deficiency results in pellagra.
Deficiency and Overdose
Severe lack of niacin causes the deficiency disease pellagra, whereas a mild deficiency slows down the metabolism decreasing cold tolerance. The symptoms of pellagra include high sensitivity to sunlight, aggression, dermatitis, red skin lesions, insomnia, weakness, mental confusion, diarrhea, and dementia (eventually). Overall, the main results of pellagra can easily be remembered as "the four D's": diarrhea, dermatitis, dementia, and death. Untreated, the disease can kill within four or five years.
Extemely high doses of niacin can cause niacin maculopathy, a thickening of the macula and retina which leads to blurred vision and blindness. [2] The recommended daily allowance of niacin is 2-12 mg a day for children, 14 mg a day for women, 16 mg a day for men, and 18 mg a day for pregnant or breast-feeding women.[3] Over 20 mg per day may produce hot flushes lasting 15-30 minutes in duration.
Discovery
Nicotinic acid was first discovered from the oxidation of nicotine. When the properties of nicotinic acid were discovered, it was thought prudent to choose a name to dissociate it from nicotine and to avoid the idea that either smoking provided vitamins or that wholesome food contained a poison. The resulting name 'niacin' was derived from nicotinic acid + vitamin. Vitamin B3 is also referred to as "vitamin PP", a name derived from the obsolete term "pellagra-preventing factor."
Bioavailability
The liver can synthesize niacin from the essential amino acid tryptophan (see below), but the synthesis is extremely slow; 60 mg of tryptophan are required to make one milligram of niacin.[4] Dietary niacin deficiency tends to occur only in areas where people eat corn, the only grain low in niacin, as a staple food, and that don't use lime during maize (corn) meal/flour production. Alkali lime releases the tryptophan from the corn so that it can be absorbed in the gut, and converted to niacin.[5]
Biosynthesis
The 5-membered aromatic heterocycle of the essential amino acid, tryptophan, is cleaved and rearranged with the alpha amino group of tryptophan into the 6-membered aromatic heterocycle of niacin by the following reaction:
Biosynthesis: Tryptophan → kynurenine → niacin
Food Sources
| Animal products: | Fruits and vegetables: | Seeds: | Fungi: |
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Other uses
Niacin plays an important role in the production of several sex and stress-related hormones, particularly those made by the adrenal gland. It also plays a role in removing toxic and harmful chemicals from the body.[5] There is evidence that doses of 500-1000 mg can terminate a bad trip on LSD, a synthetic indole, or enhance the MDMA experience. [citation needed]
Niacin, when taken in large doses, increases the level of high density lipoprotein (HDL) or "good" cholesterol in blood, and is sometimes prescribed for patients with low HDL, and at high risk of heart attack.[6] Niacin (but not niacinamide) is also used in the treatment of hyperlipidemia because it reduces very low density lipoprotein (VLDL), a precursor of low density lipoprotein (LDL) or "bad" cholesterol, secretion from the liver, and inhibits cholesterol synthesis.[7]. The main problem with the clinical use of niacin for dyslipidemia is the occurrence of skin flushing, even with moderate doses. [8] There are current attempts to create a prolonged-release formulation of the substantance, to allow it to be used more often and more comfortably. [9]
Niacin in itself is not toxic, but the chemicals converted by niacin are toxic to the skin and liver in overdose, and high doses of niacin should only be reached with gradual increase. Studies in laboratory animals have demonstrated behavioral changes when large doses of niacin are given.[10]
There is a popular belief that Niacin may be used to mask marijuana use in urine tests,[citation needed] although scientific evidence is not available as proof for this.
Industrial use
Nicotinic acid reacts with hemoglobin and myoglobin in meat to form a brightly coloured complex, and thus has been used as a food additive, typically to improve the colour of minced (ground) meat. Niacin is licensed as a food colouring agent in some countries.
Also, found in Red Bull Energy Drinks.
ReferencesISBN links support NWE through referral fees
- ↑ Merck Index, 11th Edition, 6435.
- ↑ JD Gass, Nictonic Acid Maculopathy, Am. J. Opthamology, 1973;76:500-10
- ↑ Jane Higdon, "Niacin", Micronutrient Information Center, Linus Pauling Institute
- ↑ Oxidization Reactions of Niacin from the Linus Pauling Institute at Oregon State University Linus Pauling Institute.
- ↑ 5.0 5.1 Vitamin B3 University of Maryland Medical Center.
- ↑ Postgraduate Medicine
- ↑ Katzung and Trevors Pharmacology Examination and Board Review 7th edition, Authors: Trevor, Anthony J. Katzung, Bertram G. and Masters, Susan B., Lange Medical Books/ McGraw-Hill 2005
- ↑ NIH Medline Plus: Niacin. http://www.nlm.nih.gov/medlineplus/ency/article/002409.htm.
- ↑ Options for therapeutic intervention: how effective are the different agents? European Heart Journal Supplements Vol 8 Suppl F Pp. F47-F53 http://eurheartjsupp.oxfordjournals.org/cgi/content/abstract/8/suppl_F/F47
- ↑ Sullivan, WT (June 10, 1958). Behavioral changes in rats and guinea pigs induced by the administration of indole 3-acetic acid and 6-aminonicotinamide. The Journal of Nutrition: 199-209.
- Feinberg School, Norwthwestern University. 2006. Nutrition Fact Sheet: Niacin (vitamin B3). NorthwesternNutrition. Retrieved January 28, 2007.
External links
Template:ChemicalSources
| Vitamins |
|---|
| All B vitamins | All D vitamins |
| Retinol (A) | Thiamine (B1) | Riboflavin (B2) | Niacin (B3) | Pantothenic acid (B5) | Pyridoxine (B6) | Biotin (B7) | Folic acid (B9) | Cyanocobalamin (B12) | Ascorbic acid (C) | Ergocalciferol (D2) | Cholecalciferol (D3) | Tocopherol (E) | Naphthoquinone (K) |
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