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

Carrots do contain beta-carotene, an active form of vitamin A that can be converted by the body into retinol as needed. —Irene Coltrinari, Vogue, 12 June 2025

Lifestyle and Habits Certain lifestyle habits can affect your skin and its moisture levels, such as: Not drinking enough water or eating a balanced diet can lead to deficiencies in certain nutrients, such as vitamin A and D, zinc, or iron. —Sherri Gordon, Health, 6 June 2025

This particular formula uses retinal, a form of vitamin A proven to work faster and more effectively than retinol. —Sarah Y. Wu, Glamour, 13 May 2025

However, pregnant people should avoid it due to its high levels of vitamin A, which can cause serious risks to the unborn.7 Also, people with gout should avoid eating beef liver and other organ meats. —Melissa Nieves, Verywell Health, 9 May 2025

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