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Vitamin A
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
Year introduced: RETINOL was see under VITAMIN A 1971-1976, was see VITAMIN A 1969-1970
Vitamin A Deficiency
A nutritional condition produced by a deficiency of VITAMIN A in the diet, characterized by NIGHT BLINDNESS and other ocular manifestations such as dryness of the conjunctiva and later of the cornea (XEROPHTHALMIA). Vitamin A deficiency is a very common problem worldwide, particularly in developing countries as a consequence of famine or shortages of vitamin A-rich foods. In the United States it is found among the urban poor, the elderly, alcoholics, and patients with malabsorption. (From Cecil Textbook of Medicine, 19th ed, p1179)
retinol acetate [Supplementary Concept]
structure given in first source
Date introduced: January 1, 1974
Tretinoin
An important regulator of GENE EXPRESSION during growth and development, and in NEOPLASMS. Tretinoin, also known as retinoic acid and derived from maternal VITAMIN A, is essential for normal GROWTH; and EMBRYONIC DEVELOPMENT. An excess of tretinoin can be teratogenic. It is used in the treatment of PSORIASIS; ACNE VULGARIS; and several other SKIN DISEASES. It has also been approved for use in promyelocytic leukemia (LEUKEMIA, PROMYELOCYTIC, ACUTE).
Year introduced: 1980(1975)
Retinaldehyde
A diterpene derived from the carotenoid VITAMIN A which functions as the active component of the visual cycle. It is the prosthetic group of RHODOPSIN (i.e., covalently bonded to ROD OPSIN as 11-cis-retinal). When stimulated by visible light, rhodopsin transforms this cis-isomer of retinal to the trans-isomer (11-trans-retinal). This transformation straightens-out the bend of the retinal molecule and causes a change in the shape of rhodopsin triggering the visual process. A series of energy-requiring enzyme-catalyzed reactions convert the 11-trans-retinal back to the cis-isomer.
Year introduced: 1991(1975)
vitamin A, pentifyllin, nicotinic acid, and vitamin E combination [Supplementary Concept]
contains 400mg pentifyllin, 100mg nicotinic acid, 30000 I.E. vitamin A & 40 I.E. vitamin E
Date introduced: December 2, 1980
boric acid, vitamin A, zinc sulfate drug combination [Supplementary Concept]
for treatment of colitis; contains zinc sulfate, boric acid & vitamin A
Date introduced: January 1, 1978
Hypervitaminosis A
A symptom complex resulting from ingesting excessive amounts of VITAMIN A.
Year introduced: 1987
vitamin A, vitamin E, vitamin K3 drug combination [Supplementary Concept]
consists of a mixture of vitamins A, E, and K3; effective in wound healing
Date introduced: June 20, 1989
allantoin, hyaluronic acid, vitamin A, vitamin E drug combinatinon [Supplementary Concept]
cream used to prevent pregnancy stretch marks
Date introduced: October 6, 1987
vitamin A, vitamin E drug combination [Supplementary Concept]
combination of above vitamins
Date introduced: July 2, 1986
vitamin A acid ethylamide [Supplementary Concept]
ethylamide of all-trans B-retinoic acid; RN given refers to cpd without isomeric designation
Date introduced: January 1, 1975
Opsins
Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.
Year introduced: 2009
Retinal Dehydrogenase
A metalloflavoprotein enzyme involved the metabolism of VITAMIN A, this enzyme catalyzes the oxidation of RETINAL to RETINOIC ACID, using both NAD+ and FAD coenzymes. It also acts on both the 11-trans- and 13-cis-forms of RETINAL.
Year introduced: 2006(1977)
beta Carotene
A carotenoid that is a precursor of VITAMIN A. Beta carotene is administered to reduce the severity of photosensitivity reactions in patients with erythropoietic protoporphyria (PORPHYRIA, ERYTHROPOIETIC).
Year introduced: 1997
Xerophthalmia
Dryness of the eye surfaces caused by deficiency of tears or conjunctival secretions. It may be associated with vitamin A deficiency, trauma, or any condition in which the eyelids do not close completely.
Retinol-Binding Proteins
Proteins which bind with RETINOL. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of about 21 kDa. The retinol-protein complex (MW=80-90 kDa) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14 kDa and carries retinol as a noncovalently bound ligand.
Year introduced: 1976
Retinoids
A group of tetraterpenes, with four terpene units joined head-to-tail. Biologically active members of this class are used clinically in the treatment of severe cystic ACNE; PSORIASIS; and other disorders of keratinization.
Year introduced: 1984
Retinal Pigments
Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.
Fish Oils
Oils high in unsaturated fats extracted from the bodies of fish or fish parts, especially the LIVER. Those from the liver are usually high in VITAMIN A. The oils are used as DIETARY SUPPLEMENTS. They are also used in soaps and detergents and as protective coatings.
Year introduced: 1983