vitamin A

American  

noun

1. a yellow, fat-soluble, solid terpene alcohol, C 20 H 30 O, obtained from carotene and occurring in green and yellow vegetables, egg yolk, etc.: essential to growth, the protection of epithelial tissue, and the prevention of night blindness.

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vitamin A British  

noun

1. Also called: vitamin A1.   retinol.  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: C 20 H 30 O

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vitamin A Scientific  

1. 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: C ₂₀ H ₃₀ O.

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Etymology

Origin of vitamin A

First recorded in 1920–25

Example Sentences

See Examples For:

vitamin A

Scientists at Johns Hopkins University have uncovered how humans develop sharp central vision before birth, identifying a carefully timed interaction between a vitamin A derived molecule and thyroid hormones in the retina.

From Science Daily ● Jul. 9, 2026

Those which are particularly toxic to the liver when taken in high doses include vitamin A, glutamine, ashwagandha and green tea extract.

From BBC ● Jun. 20, 2026

Some were linked to retinoic acid, an active metabolite of vitamin A that is known to promote neuronal differentiation.

From Science Daily ● May 27, 2026

“Inadequate nutrition, particularly vitamin A deficiency, can impair the lining of the digestive tract, predisposing birds to inflammation and secondary illness.”

From Los Angeles Times ● Apr. 20, 2026

The precious vitamin A, found in only very meager amounts in meats, is found in the almond, the pine nut, coconuts and peanuts.

From Northern Nut Growers Report of the Proceedings at the Twenty-First Annual Meeting Cedar Rapids, Iowa, September 17, 18, and 19, 1930 by Northern Nut Growers Association