Provitamin: Difference between revisions
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* "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== |
Revision as of 15:56, 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 ![]() |