B vitamins are a group of vitamins that play important roles in many bodily functions, from producing energy to forming cells and supporting healthy immune, brain and nerve function. While B vitamins don’t necessarily give you energy, “What [they] do is take that food and help convert to energy, they run all these processes and help the body build and rejuvenate itself,” says Mayo Clinic’s Katherine Zeratsky. Even with all of their potential health benefits, it’s still necessary to consult with your doctor to see if a B vitamin supplement is right for you.