Bad nerves are treated with B vitamins, usually vitamin B1 and vitamin B12, of which vitamin B12 is involved in the synthesis of nerve myelin sheaths and therefore promotes myelin regeneration. The application of vitamin B12 is more effective in patients with demyelinating disease due to nerve myelin damage, and this therapeutic effect is only for peripheral nerves. In contrast, vitamin B1 is used as an adjuvant to improve the mental condition, which can maintain the normal activities of nerve tissue, muscle and heart, and is a vitamin necessary for the energy metabolism of the body, especially sugar metabolism, and the pharmaceutical preparation is furathiamine in addition to vitamin B1 tablets. When vitamin B is deficient, it is easy to produce multiple peripheral neuropathies as well as Wernicke’s encephalopathy and pediculosis.