Medically reviewed by Karina Tolentino, RD B vitamins (also known as vitamin B complex) are a group of eight essential nutrients that support nearly all of your body’s functions, including metabolism, ...

A B complex contains all eight B vitamins, says Yelena Wheeler, a registered dietitian nutritionist at National Coalition on Health Care. On the other hand, a B12 supplement only contains one vitamin.

A 2016 study on rats found that vitamin B-complex and vitamin B12 supplementation may help speed up the nerve regeneration process. However, the findings of animal studies are not always ...