vitamin Bc vs vitamin B

vitamin Bc and vitamin B both are nouns.

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

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

vitamin Bc: a B vitamin that is essential for cell growth and reproduction
vitamin B: originally thought to be a single vitamin but now separated into several B vitamins

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

vitamin Bc (noun)	vitamin B (noun)
a B vitamin that is essential for cell growth and reproduction	originally thought to be a single vitamin but now separated into several B vitamins