Provitamin: Difference between revisions
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{{Short description|Substances animals can metabolize into vitamins}} | {{Short description|Substances animals can metabolize into vitamins}} | ||
A '''provitamin''' is a substance that may be converted within the body to a [[vitamin]]. The term '''previtamin''' is a synonym. | A '''provitamin''' is a substance that may be converted within the body to a [[vitamin]]. The term '''previtamin''' is a synonym. | ||
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The term "provitamin" is used when it is desirable to label a substance with little or no vitamin activity, but which can be converted to an active form by normal [[metabolism|metabolic]] processes. | The term "provitamin" is used when it is desirable to label a substance with little or no vitamin activity, but which can be converted to an active form by normal [[metabolism|metabolic]] processes. | ||
==Example== | ==Example== <!--T:3--> | ||
Some provitamins are: | Some provitamins are: | ||
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* "Provitamin A" is a name for [[Beta-Carotene|β-carotene]], which has only about 1/6 the [[biological activity]] of [[retinol]] ([[vitamin A]]); the body uses an [[enzyme]] to convert β-carotene to retinol. In other contexts, both β-carotene and retinol are simply considered to be different forms ([[vitamer]]s) of vitamin A. | * "Provitamin A" is a name for [[Beta-Carotene|β-carotene]], which has only about 1/6 the [[biological activity]] of [[retinol]] ([[vitamin A]]); the body uses an [[enzyme]] to convert β-carotene to retinol. In other contexts, both β-carotene and retinol are simply considered to be different forms ([[vitamer]]s) of vitamin A. | ||
* "Provitamin B5" is a name for [[panthenol]], which may be converted in the body to vitamin B<sub>5</sub> ([[pantothenic acid]]). | * "Provitamin B5" is a name for [[panthenol]], which may be converted in the body to vitamin B<sub>5</sub> ([[pantothenic acid]]). | ||
* [[Menadione]] is a synthetic provitamin of [[vitamin K]]. | * [[Menadione]] is a synthetic provitamin of [[vitamin K]]. | ||
* Provitamin [[vitamin D|D<sub>2</sub>]] is [[ergosterol]], and provitamin D<sub>3</sub> is [[7-dehydrocholesterol]]. They are converted by UV light into vitamin D. | * Provitamin [[vitamin D|D<sub>2</sub>]] is [[ergosterol]], and provitamin D<sub>3</sub> is [[7-dehydrocholesterol]]. They are converted by UV light into vitamin D. The human body produces provitamin D<sub>3</sub> naturally; deficiency is usually caused by a lack of sun exposure, not a lack of the provitamin. | ||
==External links== | ==External links== <!--T:5--> | ||
*[https://deerforia.com/ Vitamin Gummies] | *[https://deerforia.com/ Vitamin Gummies] | ||
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{{二次利用|date=5 December 2023}} | {{二次利用|date=5 December 2023}} | ||
[[Category:Vitamins]] | [[Category:Vitamins]] | ||
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Latest revision as of 15:57, 21 February 2024
A provitamin is a substance that may be converted within the body to a vitamin. The term previtamin is a synonym.
The term "provitamin" is used when it is desirable to label a substance with little or no vitamin activity, but which can be converted to an active form by normal metabolic processes.
Example
Some provitamins are:
- "Provitamin A" is a name for β-carotene, which has only about 1/6 the biological activity of retinol (vitamin A); the body uses an enzyme to convert β-carotene to retinol. In other contexts, both β-carotene and retinol are simply considered to be different forms (vitamers) of vitamin A.
- "Provitamin B5" is a name for panthenol, which may be converted in the body to vitamin B5 (pantothenic acid).
- Menadione is a synthetic provitamin of vitamin K.
- Provitamin D2 is ergosterol, and provitamin D3 is 7-dehydrocholesterol. They are converted by UV light into vitamin D. The human body produces provitamin D3 naturally; deficiency is usually caused by a lack of sun exposure, not a lack of the provitamin.
External links
 | この記事は、クリエイティブ・コモンズ・表示・継承ライセンス3.0のもとで公表されたウィキペディアの項目Provitamin(5 December 2023編集記事参照)を素材として二次利用しています。 Item:Q21162  |