Vitamin B6 deficiency is caused by improper food cooking or too monotonous varieties. Malabsorption can also lead to vitamin B6 deficiency. Vitamin B6 dependence syndrome is a structural and functional defect of the innate metabolic enzyme kynurenine enzyme. At this time, the amount of vitamin B6 required is 5 to 10 times that required by normal children, and vitamin B6 deficiency is very likely to occur. In infancy, the main manifestations of vitamin B6 deficiency and dependence are systemic convulsions, leading to mental retardation. At the same time, it is often accompanied by gastrointestinal symptoms such as vomiting and diarrhea. Other manifestations include peripheral neuritis, dermatitis and anemia.