Vitamin B complex are necessary for vital functions and essential for formation of co-enzyme, necessary for enzymatic reaction . Example – Vitamin B1 – also called thiamine – required for TPP (Thiamine Pyrophosphate), Vitamin B2 also called riboflavin – required for FMN/FAD formation, Vitamin B3 also called niacin or nicotinic acid – required for formation of NAD, NADP