https://wiki.tiffa.net/w/index.php?action=history&feed=atom&title=Translations%3ANiacin%2F49%2FenTranslations:Niacin/49/en - Revision history2026-11-12T19:30:52ZRevision history for this page on the wikiMediaWiki 1.43.0https://wiki.tiffa.net/w/index.php?title=Translations:Niacin/49/en&diff=117749&oldid=prevFuzzyBot: Importing a new version from external source2024-02-20T00:42:52Z<p>Importing a new version from external source</p>
<p><b>New page</b></p><div>Niacin and nicotinamide are both converted into the [[coenzyme]] NAD. NAD converts to NADP by phosphorylation in the presence of the enzyme [[NAD+ kinase]]. High energy requirements (brain) or high turnover rate (gut, skin) organs are usually the most susceptible to their deficiency. In the liver, niacinamide is converted to storage [[nicotinamide adenine dinucleotide]] (NAD). As needed, liver NAD is hydrolyzed to niacinamide and niacin for transport to tissues, there reconverted to NAD to serve as an enzyme cofactor. Excess niacin is methylated in the liver to N<sup>1</sup>-methylnicotinamide (NMN) and excreted in urine as such or as the oxidized metabolite [[N1-Methyl-2-pyridone-5-carboxamide|N<sup>1</sup>-methyl-2-pyridone-5-carboxamide]] (2-pyridone). Decreased urinary content of these metabolites is a measure of niacin deficiency.<br />
[[Image:Tryptophan metabolism.svg|thumb|300px|Niacin, [[serotonin]] (5-hydroxytryptamine), and [[melatonin]] [[biosynthesis]] from [[tryptophan]]]]</div>FuzzyBot