A provitamin is a substance that may be converted within the body to a vitamin. ^[1] The term previtamin is a synonym. ^[2]

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.^{[ citation needed]}

Example

Some provitamins are:

• "Provitamin A" is a name for β-carotene, ^[1] 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. ^[1] The human body produces provitamin D₃ naturally; deficiency is usually caused by a lack of sun exposure, not a lack of the provitamin. ^[3]

References

External links

• Vitamin Gummies

This biochemistry article is a stub. You can help Wikipedia by expanding it.

• v
• t
• e