vitamin a2

from WordNet (r) 3.0 (2006)

vitamin A2
    n 1: a viscous alcohol that is less active in mammals than is
         vitamin A1 [syn: {vitamin A2}, {dehydroretinol}]

from The Collaborative International Dictionary of English v.0.48

vitamin A2 \vitamin A2\ n.
   dehydroretinol ({C20H28O}), one of the substances also called
   {vitamin A}. It has about 40% of the bioactivity of vitamin
   A1.

   Syn: dehydroretinol.
        [WordNet 1.5 +PJC]