A crystalline sterol, C28H43OH, synthesized by yeast from sugars or derived from ergot and converted to vitamin D2 when exposed to ultraviolet radiation.

• 麦角甾醇结晶甾醇，C28H43OH，由糖中的酵母合成或由麦角提炼而成，当受紫外线照射时可转化成维生素D2