C20H30O

from The Collaborative International Dictionary of English v.0.48

vitamin A1 \vitamin A1\ n.
   retinol ({C20H30O}), one of the substances also called
   {vitamin A}. It is also called more specifically {vitamin A
   alcohol}. It is a required factor for human nutrition. The
   USP unit of activity is equal to 0.30 micrograms of retinol.

   Syn: retinol.
        [WordNet 1.5 +PJC]

from The Collaborative International Dictionary of English v.0.48

axerophthol \axerophthol\ n.
   1. a vitamin essential for normal vision ({C20H30O}); it
      prevents night blindness or inflammation or dryness of the
      eyes; same as {vitamin A}. One U.S.P. unit of vitamin A is
      equivalent to 0.30 micrograms of pure vitamin A alcohol.

   Syn: vitamin A; vitamin A alcohol; antiophthalmic factor;
        biosterol; retinol; A.
        [WordNet 1.5 +PJC]