微量元素对于人体来讲是极重要的微营养素,在体内参与机体许多重要生理过程,如物质代谢、免疫功能、激素调节、基因表达的调控等.但对人来说却是适量有益,过量或不足均对人有害,如地氟病、地甲病及大脖子病均为某种微量元素不足所致. Trace elements are extremely important micro nutrients for the human body and are involved in many important physiological processes in the body, such as metabolism, immune function, hormone regulation, regulation of gene expression, etc. However, it is moderate, Insufficient are harmful to people, such as fluorosis, toremia and neck disease are due to a trace element deficiency.