vitamin A

vitamin, class of molecules with related biological function

AI overview

Vitamin A is a molecule that your body needs to help with important functions like vision, immune system health, and skin maintenance. You get it from foods like carrots, sweet potatoes, and leafy greens, and your body stores it for use when dietary intake is low.

AI-generated from the Wikipedia summary — may contain errors.

Research

62,541 papers

Vitamin A.ReviewLancet (London, England) · 1995Bates CJDOI: 10.1016/s0140-6736(95)91157-x
Vitamin A physiology.ReviewJAMA · 1970Roels OA
Vitamin A.Advances in nutrition (Bethesda, Md.) · 2017Debelo H, Novotny JA, Ferruzzi MGDOI: 10.3945/an.116.014720
Vitamin A in nature.ReviewWorld review of nutrition and dietetics · 2012McLaren DS, Kraemer KDOI: 10.1159/000258434
Vitamin A.ReviewProgress in food & nutrition science · 1975McLaren DS
Human vitamin A deficiency.ReviewWorld review of nutrition and dietetics · 1975Srikantia SGDOI: 10.1159/000396065
Vitamin A in pregnancy and lactation.ReviewThe Proceedings of the Nutrition Society · 1983Bates CJDOI: 10.1079/pns19830008
Vitamin A and protein metabolism.ReviewJournal of agricultural and food chemistry · 1972Roels OA, Mack JPDOI: 10.1021/jf60184a034

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Wikidata facts

Image: Vitamin-A-Synthese.png

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Commons category: Vitamin A

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wikidata.org

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Article

Vitamin A is a fat-soluble vitamin that is an essential nutrient. The term "vitamin A" encompasses a group of chemically related organic compounds that includes retinol, retinyl esters, and several provitamin (precursor) carotenoids, most notably β-carotene (beta-carotene). Vitamin A has multiple functions: growth during embryo development, maintaining the immune system, and healthy vision. For aiding vision specifically, it combines with the protein opsin to form rhodopsin, the light-absorbing molecule necessary for both low-light (scotopic vision) and color vision.

Vitamin A occurs as two principal forms in foods: 1) retinoids, found in animal-sourced foods, either as retinol or bound to a fatty acid to become a retinyl ester, and 2) the carotenoids α-carotene (alpha-carotene), β-carotene, γ-carotene (gamma-carotene), and the xanthophyll beta-cryptoxanthin (all of which contain β-ionone rings) that function as provitamin A in herbivore and omnivore animals which possess the enzymes that cleave and convert provitamin carotenoids to retinol. Some carnivore species lack this enzyme. The other carotenoids do not have retinoid activity.