vitamin A

vitamin A

n.

A fat-soluble vitamin or a mixture of vitamins, especially vitamin A₁ or a mixture of vitamins A₁ and A₂, occurring principally in fish-liver oils, milk, and some yellow and dark green vegetables, and functioning in normal cell growth and development. Its deficiency causes hardening and roughening of the skin, night blindness, and degeneration of mucous membranes. Also called retinol.

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vitamin A₁

n.

A yellow crystalline compound, C₂₀H₃₀O, extracted from egg yolks, milk, and cod-liver oil.

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vitamin A₂

n.

A golden yellow oil, C₂₀H₂₈O, occurring chiefly in the livers of freshwater fish and having about 40 percent of the biological activity of vitamin A₁.

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vitamin A

n

(Chemistry / Elements & Compounds) a fat-soluble yellow unsaturated alcohol occurring in green and yellow vegetables (esp carrots), butter, egg yolk, and fish-liver oil (esp halibut oil). It is essential for the prevention of night blindness and the protection of epithelial tissue. Formula: C₂₀H₃₀O Also called vitamin A₁ retinol

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vitamin A
n.

a yellow, fat-soluble terpene alcohol, C₂₀H₃₀O, obtained from carotene and occurring in green and yellow vegetables, egg yolk, etc.: essential to the protection of epithelial tissue and the prevention of night blindness. Also called vitamin A₁, retinol.

[1920–25]

vitamin A2
n.

a yellow oil, C₂₀H₂₈O, similar to vitamin A, obtained from fish liver.

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vitamin A

A fat-soluble vitamin important for normal vision, tissue growth, and healthy skin. It is found in fish-liver oils, milk, green leafy vegetables, and red, orange, and yellow vegetables and fruits. A deficiency of vitamin A in humans causes poor vision at night and damage to the skin and mucous membranes. Also called retinol. Chemical formula: C₂₀H₃₀O.

Thesaurus

Noun

1.

vitamin A - any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes antiophthalmic factor, axerophthol, A fat-soluble vitamin - any vitamin that is soluble in fats retinol, vitamin A1 - an unsaturated alcohol that occurs in marine fish-liver oils and is synthesized biologically from carotene dehydroretinol, vitamin A2 - a viscous alcohol that is less active in mammals than is vitamin A1