/kal sif"euh rawl', -rol'/ , n. Biochem.
a fat-soluble, crystalline, unsaturated alcohol, C 28 H 43 OH, occurring in milk, fish-liver oils, etc., produced by ultraviolet irradiation of ergosterol, and used as a dietary supplement, as in fortified milk. Also called vitamin D 2 .
[ 1930-35; CALCIF(EROUS) + (ERGOST)EROL ]