Class VITAMIN

A substance, usually an organic chemical complex, present in natural products or made synthetically, which is essential in the diet of man or other higher animals. Included here are vitamin precursors and provitamins.
Subclass-Of: Biologically-active-substance
Axioms:
(=> (Vitamin ?Self)
    (Exists (?A)
            (And (Resource-Of ?Self ?A)
                 (Diet ?A)
                 (Exists (?B) (And (Performed-By ?A ?B) (Human ?B))))))