pyridoxine vs vitamin B

pyridoxine and vitamin B both are nouns.

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

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

pyridoxine: a B vitamin that is essential for metabolism of amino acids and starch
vitamin B: originally thought to be a single vitamin but now separated into several B vitamins

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

pyridoxine (noun)	vitamin B (noun)
a B vitamin that is essential for metabolism of amino acids and starch	originally thought to be a single vitamin but now separated into several B vitamins