Vitamin B is mainly involved in human digestion and absorption function and nerve conduction function. Different vitamin B deficiency may lead to different clinical manifestations. For example, vitamin B 1 deficiency can cause indigestion, sometimes numbness of hands and feet, polyneuritis and beriberi; When vitamin B2 is lacking, babies are prone to bad breath, poor sleep, mental fatigue, "oily skin" and increased dandruff. Sometimes, it will cause serious symptoms such as oral mucosal ulcer and angular stomatitis.

Vitamin B6 and vitamin B 12 are essential substances for nerve cell metabolism. When lacking, it can be manifested as abnormal skin sensation, thin yellow hair, listlessness, loss of appetite, vomiting, diarrhea, nutritional anemia and so on.

Lack of vitamin B 1 can cause beriberi; Lack of vitamin B2 can lead to cheilitis, angular stomatitis, glossitis and bursitis; Lack of vitamin B 12 will lead to pernicious anemia;