Vitamin A: Difference between revisions

Revision as of 15:38, 28 October 2009

Deficiencies of vitamin A has been associated with a number of maladies related to^[1]:

Vision: Retinal is a critical structural component of rhodopsin, the light sensitive (purple vision) pigment within rod and cone cells of the retina.

Skin: Epithelial cells require vitamin A for differentiation and maintenance - lack of vitamin A leads to keratinized and scaly skin, due to impaired gene transcription due to insufficient retinoic acid.

Reproduction: Vitamin A is essentially for the production of sperm and normal female reproductive cycles.

\beta

-carotene.

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-{{subpages}}
-{{Image|Retinol and related.png|right|250px|Retinol (Vitamin A) and related compounds.}}
-'''Vitamin A''', or '''retinol''', is the immediate precursor of two important biochemicals, [[retinal]] and [[retinoic acid]].  Ultimately, retinol is derived biochemically from [[carotene]]s such as<math>\beta</math>-[[carotene]], but is not derived from similar [[carotenoid]]s such as [[lutein]] or [[zeaxanthin]].  Retinal plays a critical role in [[vision]], while retinoic acid is an  intracellular messenger chemical that affects [[gene]] [[transcription]].  Although plants do not produce retinol, they do produce carotenes which can be converted to retinol in the gastrointestinal tract.
 == Physiological Effects ==
 Deficiencies of vitamin A has been associated with a number of maladies related to<ref>{{cite web | title = Vitamin A (Retinol) at Colorado State | url = http://www.vivo.colostate.edu/hbooks/pathphys/misc_topics/vitamina.html | accession = 20091027}}</ref>:
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 {{Image|Beta-carotene.png|left|500px|<math>\beta</math>-carotene.}}
-== References ==
-<references/>