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

About a quarter of U.S. adults wrongly believe vitamin A can prevent measles infections, according to a KFF poll conducted last year.

From Salon • Mar. 19, 2026

In laboratory experiments, retinoic acid can cause cancer cells to stop growing or die, contributing to the belief that vitamin A has anti-cancer properties.

From Science Daily • Jan. 16, 2026

He also touted cod liver oil as a measles treatment, citing its “high concentrations of vitamin A and vitamin D.”

From The Wall Street Journal • Jan. 11, 2026

But any amount of potassium, magnesium, vitamin A and C — all key nutrients in banana water — is helpful, King says.

From Los Angeles Times • Dec. 15, 2025

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