noun Biochemistry.
- a colorless, crystalline, water-insoluble sterol, C28H43OH, that occurs in ergot and yeast and that, when irradiated with ultraviolet light, is converted to vitamin D.
noun
- a plant sterol that is converted into vitamin D by the action of ultraviolet radiation. Formula: C 28 H 43 OH
n.
- A crystalline sterol synthesized by yeast from sugars or derived from ergot and converted to vitamin D2 when exposed to ultraviolet radiation.