If you don’t have a nutrition department, you can register with general internal medicine or gastroenterology to check trace elements. There is no need to fast when checking trace elements, and blood is not collected from a vein, but from the fingertips. The usual tests for trace elements include calcium, iron and zinc. If you have low calcium, you will have poor bone development, so when you have low calcium, you can pay attention to supplementing milk, shrimp and other substances that contain high calcium. Iron deficiency can easily lead to iron deficiency anemia, resulting in low hemoglobin, dizziness, weakness, and pallor, so you can supplement foods high in iron, and supplement folic acid and vitamin C to promote the synthesis of hemoglobin. Zinc also plays a very broad and important role in the human body, especially to promote the development of the nervous system, also pay attention to supplement oysters and other foods high in zinc.