Answer:

BSIX

Answer	Crossword Clue
BSIX	Vitamin known as pyridoxine
BSIX	Vitamin name, or a bingo call
BSIX	Vitamin found in meat

BSIX	Possible bingo call
BSIX	Vitamin whose name could be a bingo call
BSIX	Vitamin whose name sounds like a bingo call
BSIX	Vitamin that could also be a bingo call
BSIX	Vitamin whose name rhymes with a car engine