Chemistry:Provitamin

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(1)" is a name for all-trans-β-carotene, which has only about 1/6 the biological activity of retinol, in the all-trans-form /(vitamin A(1)); the body uses an enzyme to convert all-trans-β-carotene to all-trans-retinol. In other contexts, both all-trans-β-carotene and retinol, in the all-trans-form, are simply considered to be different forms (vitamers) of vitamin A(1).
• "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

• Vitamin Gummies