extrinsic
/ek-ˈstrin-zik/
adjective
not forming part of or belonging to a thing : extraneous
originating from or on the outside; especially : originating outside a part and acting upon the part as a whole
external
extrinsic extraneous foreign alien mean external to a thing, its essential nature, or its original character. extrinsic applies to what is distinctly outside the thing in question or is not contained in or derived from its essential nature. extraneous applies to what is on or comes from the outside and may or may not be capable of becoming an essential part.
noun
vitamin b12