provitamin A

provitamin /pro·vi·ta·min/ (-vi´tah-min) a precursor of a vitamin.

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provitamin A  usually β-carotene, sometimes including any of the provitamin A carotenoids.

provitamin D2  ergosterol.

provitamin D3  7-dehydrocholesterol.

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provitamin A

n.

Any of the carotenoids that are precursors of vitamin A and exhibit qualitatively the biological activity of beta-carotene; they are present in fish-liver oils, egg yolk, milk products, green-leaf or yellow vegetables, and fruits.

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provitamin

a substance, e.g. ergosterol, from which the animal organism can form a vitamin.

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provitamin A

see carotene.