#vitamin_A__antiophthalmic_factor__axerophthol__A  any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
  supertype:  fat-soluble_vitamin__fatsolublevitamin  any vitamin that is soluble in fats
  subtype:  vitamin_A1__retinol  an unsaturated alcohol that occurs in marine fish-liver oils and is synthesized biologically from carotene
  subtype:  vitamin_A2__dehydroretinol  a viscous alcohol that is less active in mammals than is vitamin A1

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