biotin vs vitamin B

biotin and vitamin B both are nouns.

Word	Noun	Adjective	Verb	Adverb
biotin	Yes	No	No	No
vitamin B	Yes	No	No	No

As nouns, vitamin B is a hypernym of biotin; that is, vitamin B is a word with a broader meaning than biotin:

biotin: a B vitamin that aids in body growth
vitamin B: originally thought to be a single vitamin but now separated into several B vitamins

Other hypernyms of biotin include B-complex vitamin, B, B complex, B vitamin, vitamin B complex.

biotin (noun)	vitamin B (noun)
a B vitamin that aids in body growth	originally thought to be a single vitamin but now separated into several B vitamins