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

It’s made by combining vitamin A with a type of fat called palmitic acid. —William Truswell, Verywell Health, 30 Oct. 2024

Chief among them is retinal (like retinol, but an even stronger form of the vitamin A derivative) to trigger collagen production that’ll smooth out fine lines and wrinkles. —Emily Orofino, Vogue, 23 Oct. 2024

Today’s recipe for lentil stew includes lycopene-rich tomatoes and sweet potatoes, which are full of vitamin A and potassium. —Bethany Thayer, Detroit Free Press, 19 Oct. 2024

Three ounces of skipjack tuna, for example, contain iron, calcium, magnesium, phosphorus, zinc, thiamin, folate, vitamin B12, vitamin A, and a whopping 18 grams of protein, per the U.S. Department of Agriculture. —Daryl Austin, USA TODAY, 8 Oct. 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