Vitamin - a, Biology


  1. Discovered by Macollum.
  2. Also known as Retinol / Antixeropthalmic vitamin / Auxerophthol.
  3. It is vitamin for normal vision. It forms retinal pigments rhodopsin & iodopsin.
  4. It is anti-infective vitamin.
  5. It is stored in liver.
  6. Its deficiency cause toad skin (follicular hyperkeratosis).
  7. Its deficiency causes night blindness (Nyctolopia / Henerolopia).
  8. It's deficiency causes xeropthalmia, in which cornea becomes dry, keratinization of cornea start, tear formation absent & it may lead to total blindness.
  9. Keratomalesia is due to prolonged deficiency of vitamin A, in which keratinization & degeneration of cornea takes place.
  10. Vitamin A prevents keratin deposition in surface cells and glandular epithelium.
  11. Source of vitamin A - carrot, guava, papaya, mango, liver, egg, yolk & cod liver oil.
Posted Date: 10/9/2012 6:11:02 AM | Location : United States

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