High serum vitamin B12 may be related to consuming too much food containing vitamin B12, true erythrocytosis or excessive heavy metal cobalt, which can be improved by dietary modification and medication. 1. Consume more food containing vitamin B12: Foods rich in vitamin B12 include carrots, animal liver, chicken, beef and milk. Serum vitamin B12 is high due to diet, do not worry too much, it is recommended to reduce food intake, reasonable control of diet, after a period of time, the serum vitamin B12 level will gradually return to normal. 2. True erythrocytosis: serum vitamin B12 can promote the generation of red blood cells, leading to an increase in red blood cells in the patient’s body. Rucotinib, hydroxyurea and other drugs that inhibit erythrocyte proliferation can be used to reduce cell proliferation and alleviate the phenomenon of high serum vitamin B12. 3. Heavy metal cobalt content is too much: vitamin B12 is also known as cobalamin, if there is heavy metal cobalt poisoning, it will lead to an increase in vitamin B12 content in the body. Heavy metal poisoning, you must immediately go to the hospital, under the guidance of the doctor to induce vomiting, the more serious patients need hemodialysis treatment. The above medications should be used regularly under medical supervision. If it is clear that the high level of serum vitamin B12 is caused by disease factors, you should go to the hospital and receive targeted treatment according to the doctor’s instructions.