What vitamin is David P. Ballou known for studying?
David Ballou:  He is best known for his development of rapid-reaction techniques, including stopped flow and rapid freeze-quench EPR methods, as tools to study the mechanisms of enzymes containing flavin, iron, cobalamin, or pyridoxal phosphate cofactors. Vitamin B12: Vitamin B, also called cobalamin, is a water-soluble vitamin that has a key role in the normal functioning of the brain and nervous system via the synthesis of myelin (myelinogenesis), and the formation of red blood cells.
Vitamin B