Matches in DBpedia 2015-10 for { <http://dbpedia.org/resource/Vitamin_A> ?p ?o }
- Vitamin_A abstract "Vitamin A is a group of unsaturated nutritional organic compounds, that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids, and beta-carotene. Vitamin A has multiple functions: it is important for growth and development, for the maintenance of the immune system and good vision. Vitamin A is needed by the retina of the eye in the form of retinal, which combines with protein opsin to form rhodopsin, the light-absorbing molecule necessary for both low-light (scotopic vision) and color vision. Vitamin A also functions in a very different role as retinoic acid (an irreversibly oxidized form of retinol), which is an important hormone-like growth factor for epithelial and other cells.In foods of animal origin, the major form of vitamin A is an ester, primarily retinyl palmitate, which is converted to retinol (chemically an alcohol) in the small intestine. The retinol form functions as a storage form of the vitamin, and can be converted to and from its visually active aldehyde form, retinal.All forms of vitamin A have a beta-ionone ring to which an isoprenoid chain is attached, called a retinyl group. Both structural features are essential for vitamin activity. The orange pigment of carrots (beta-carotene) can be represented as two connected retinyl groups, which are used in the body to contribute to vitamin A levels. Alpha-carotene and gamma-carotene also have a single retinyl group, which give them some vitamin activity. None of the other carotenes have vitamin activity. The carotenoid beta-cryptoxanthin possesses an ionone group and has vitamin activity in humans.Vitamin A can be found in two principal forms in foods:Retinol, the form of vitamin A absorbed when eating animal food sources, is a yellow, fat-soluble substance. Since the pure alcohol form is unstable, the vitamin is found in tissues in a form of retinyl ester. It is also commercially produced and administered as esters such as retinyl acetate or palmitate.The carotenes alpha-carotene, beta-carotene, gamma-carotene; and the xanthophyll beta-cryptoxanthin (all of which contain beta-ionone rings), but no other carotenoids, function as provitamin A in herbivores and omnivore animals, which possess the enzyme beta-carotene 15,15'-dioxygenase which cleaves beta-carotene in the intestinal mucosa and converts it to retinol. In general, carnivores are poor converters of ionone-containing carotenoids, and pure carnivores such as cats and ferrets lack beta-carotene 15,15'-dioxygenase and cannot convert any carotenoids to retinal (resulting in none of the carotenoids being forms of vitamin A for these species).↑ ↑ 2.0 2.1 ↑ ↑ ↑ ↑ ↑ ↑".
- Vitamin_A thumbnail All-trans-Retinol.svg?width=300.
- Vitamin_A wikiPageExternalLink Vitamin_A_Supplementation.pdf.
- Vitamin_A wikiPageExternalLink Investing_in_the_future.pdf.
- Vitamin_A wikiPageExternalLink index.html.
- Vitamin_A wikiPageID "54114".
- Vitamin_A wikiPageLength "48721".
- Vitamin_A wikiPageOutDegree "153".
- Vitamin_A wikiPageRevisionID "681495268".
- Vitamin_A wikiPageWikiLink 13-cis-retinoic_acid.
- Vitamin_A wikiPageWikiLink 13-cis_retinoic_acid.
- Vitamin_A wikiPageWikiLink Acne.
- Vitamin_A wikiPageWikiLink Acne_vulgaris.
- Vitamin_A wikiPageWikiLink Alcohol.
- Vitamin_A wikiPageWikiLink Aldehyde.
- Vitamin_A wikiPageWikiLink Alpha-Carotene.
- Vitamin_A wikiPageWikiLink Alpha-carotene.
- Vitamin_A wikiPageWikiLink Anorexia_(symptom).
- Vitamin_A wikiPageWikiLink Apoptosis.
- Vitamin_A wikiPageWikiLink Apricot.
- Vitamin_A wikiPageWikiLink Aurantiasis_cutis.
- Vitamin_A wikiPageWikiLink Beta-Carotene.
- Vitamin_A wikiPageWikiLink Beta-carotene.
- Vitamin_A wikiPageWikiLink Beta-carotene_15,15-dioxygenase.
- Vitamin_A wikiPageWikiLink Beta-cryptoxanthin.
- Vitamin_A wikiPageWikiLink Beta-ionone.
- Vitamin_A wikiPageWikiLink Birth_defects.
- Vitamin_A wikiPageWikiLink Bitots_spots.
- Vitamin_A wikiPageWikiLink Broccoli.
- Vitamin_A wikiPageWikiLink Burkina_Faso.
- Vitamin_A wikiPageWikiLink Butter.
- Vitamin_A wikiPageWikiLink Canadian_International_Development_Agency.
- Vitamin_A wikiPageWikiLink Cantaloupe.
- Vitamin_A wikiPageWikiLink Cantaloupe_melon.
- Vitamin_A wikiPageWikiLink Carbohydrate.
- Vitamin_A wikiPageWikiLink Carotene.
- Vitamin_A wikiPageWikiLink Carotenodermia.
- Vitamin_A wikiPageWikiLink Carotenoid.
- Vitamin_A wikiPageWikiLink Carotenoids.
- Vitamin_A wikiPageWikiLink Carotenosis.
- Vitamin_A wikiPageWikiLink Carrot.
- Vitamin_A wikiPageWikiLink Category:Biomolecules.
- Vitamin_A wikiPageWikiLink Category:Unsaturated_compounds.
- Vitamin_A wikiPageWikiLink Category:Vitamins.
- Vitamin_A wikiPageWikiLink Cheddar_cheese.
- Vitamin_A wikiPageWikiLink Child_mortality.
- Vitamin_A wikiPageWikiLink Cod_liver_oil.
- Vitamin_A wikiPageWikiLink Collard_greens.
- Vitamin_A wikiPageWikiLink Color_vision.
- Vitamin_A wikiPageWikiLink Congenital_disorder.
- Vitamin_A wikiPageWikiLink Cryptoxanthin.
- Vitamin_A wikiPageWikiLink David_Adriaan_van_Dorp.
- Vitamin_A wikiPageWikiLink Diet_(nutrition).
- Vitamin_A wikiPageWikiLink Dietary.
- Vitamin_A wikiPageWikiLink Dietary_Reference_Intake.
- Vitamin_A wikiPageWikiLink Edible_seaweed.
- Vitamin_A wikiPageWikiLink Egg_(food).
- Vitamin_A wikiPageWikiLink Elmer_McCollum.
- Vitamin_A wikiPageWikiLink Epithelial.
- Vitamin_A wikiPageWikiLink Epithelium.
- Vitamin_A wikiPageWikiLink Ester.
- Vitamin_A wikiPageWikiLink Fat.
- Vitamin_A wikiPageWikiLink Food.
- Vitamin_A wikiPageWikiLink François_Magendie.
- Vitamin_A wikiPageWikiLink Frederick_Gowland_Hopkins.
- Vitamin_A wikiPageWikiLink Gamma-Carotene.
- Vitamin_A wikiPageWikiLink Gamma-carotene.
- Vitamin_A wikiPageWikiLink Gram.
- Vitamin_A wikiPageWikiLink Growth_factor.
- Vitamin_A wikiPageWikiLink Haematopoiesis.
- Vitamin_A wikiPageWikiLink Harry_Steenbock.
- Vitamin_A wikiPageWikiLink Helen_Keller_International.
- Vitamin_A wikiPageWikiLink Hematopoiesis.
- Vitamin_A wikiPageWikiLink Herbivore.
- Vitamin_A wikiPageWikiLink Hormone.
- Vitamin_A wikiPageWikiLink Hox.
- Vitamin_A wikiPageWikiLink Hox_gene.
- Vitamin_A wikiPageWikiLink Hypervitaminosis_A.
- Vitamin_A wikiPageWikiLink Idiopathic_intracranial_hypertension.
- Vitamin_A wikiPageWikiLink Immune_system.
- Vitamin_A wikiPageWikiLink Insomnia.
- Vitamin_A wikiPageWikiLink Institute_of_Medicine.
- Vitamin_A wikiPageWikiLink International_unit.
- Vitamin_A wikiPageWikiLink Ionone.
- Vitamin_A wikiPageWikiLink Isoprene.
- Vitamin_A wikiPageWikiLink Isotretinoin.
- Vitamin_A wikiPageWikiLink Kale.
- Vitamin_A wikiPageWikiLink Keratomalacia.
- Vitamin_A wikiPageWikiLink Keratosis_pilaris.
- Vitamin_A wikiPageWikiLink Kilogram.
- Vitamin_A wikiPageWikiLink Lafayette_Mendel.
- Vitamin_A wikiPageWikiLink Liver_(food).
- Vitamin_A wikiPageWikiLink Low-fat_diet.
- Vitamin_A wikiPageWikiLink Mango.
- Vitamin_A wikiPageWikiLink Microgram.
- Vitamin_A wikiPageWikiLink Micronutrient_Initiative.
- Vitamin_A wikiPageWikiLink Milk.
- Vitamin_A wikiPageWikiLink Millennium_Development_Goals.
- Vitamin_A wikiPageWikiLink National_Academy_of_Medicine.
- Vitamin_A wikiPageWikiLink National_Academy_of_Sciences.