vitamin A

noun

: any of several fat-soluble vitamins (such as retinol) that are found especially in green or orange vegetables (such as carrots or spinach) and in animal products (such as egg yolk, butter, or liver) and whose deficiency in the animal body causes epithelial tissues to become keratinous (as in the eye with resulting visual defects)

Examples of vitamin A in a Sentence

Recent Examples on the Web

For instance, without enough vitamin A — found in eggs, fish and vegetables — children in Gaza risk developing poor eyesight. —Lauren Weber, Washington Post, 4 Apr. 2024

Retinol is a form of vitamin A and is a popular skincare ingredient that is used to improve the appearance of fine lines and wrinkles on aging skin. —Parija Kavilanz, CNN, 12 Mar. 2024

One, a pill that blocks certain cells from accessing vitamin A, might be able to limit fertility without flooding the body with hormones; another is an injection that temporarily blocks up the reproductive plumbing. —Katherine J. Wu, The Atlantic, 3 Apr. 2024

Grapefruits also contain vitamin A, which helps support eye health and cell growth. —Clare Mulroy, USA TODAY, 24 Mar. 2024

Experts do not recommend giving vitamin A to prevent measles. —Dr. Angela Zhang, ABC News, 8 Jan. 2024

Retinol truly deserves its own essay, but the short version is this: The vitamin A derivative boosts collagen production and increases the rate of cellular turnover. —Sarah Y. Wu, Glamour, 8 Mar. 2024

Retinoids, a group of chemical compounds derived from vitamin A, commonly cause issues for tweens and young teens who don’t need them, dermatologists said. —Katie Mogg, NBC News, 29 Feb. 2024

Its formula has vitamin A and E to promote nail health and vitamin B5 to protect nail structure. —Addie Morton, Southern Living, 6 Feb. 2024

Word History

First Known Use

circa 1920, in the meaning defined above

Kids Definition

vitamin A

noun

: any of several vitamins or a mixture of them that are found especially in green and orange vegetables (as carrots or spinach) and animal products (as egg yolk, butter, or liver) and are needed especially for good vision

Medical Definition

vitamin A

noun

: any of several fat-soluble vitamins or a mixture of two or more of them whose lack in the animal body causes keratinization of epithelial tissues (as in the eye with resulting night blindness and xerophthalmia): as

a

: a pale yellow crystalline highly unsaturated alicyclic alcohol C₂₀H₂₉OH that is found in animal products (as egg yolk, milk, and butter) and especially in marine fish-liver oils (as of cod, halibut, and shark) and that is used in various forms in medicine and nutrition

called also retinol, vitamin A₁

b

: a yellow viscous liquid alicyclic alcohol C₂₀H₂₇OH that contains one more double bond in a molecule than vitamin A₁ and is less active biologically in mammals and that occurs especially in the liver oil of freshwater fish

called also vitamin A₂