Definitions for vitamin a
Random House Webster's College Dictionary
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.
Category: Biochemistry, Nutrition
Ref: Also called vitamin A1 , retinol. 1
Origin of vitamin A:
1920–25
vitamin A 2(n.)
a yellow oil, C20H28O, similar to vitamin A, obtained from fish liver.
Category: Biochemistry, Nutrition
Princeton's WordNet
vitamin A, antiophthalmic factor, axerophthol, A(noun)
any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
Wiktionary
vitamin A(Noun)
Any of several closely related fat-soluble vitamins that are essential for normal vision; retinol.
U.S. National Library of Medicine
Vitamin A
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
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