The contraindications of vitamin b12 have not yet been clarified, and there is no such thing as who can’t eat it, but people suffering from gout, folic acid deficiency or neurological damage are not suitable to eat vitamin b12. 1. Gout: gout patients are not suitable to eat vitamin b12, otherwise it may accelerate the nucleotide dissolution, which leads to increased levels of uric acid in the blood, aggravating the condition of gout. 2. Folic acid deficiency: if vitamin b12 deficiency patients are also accompanied by folic acid deficiency, it is not suitable to eat vitamin b12 alone, to avoid masking the symptoms of folic acid deficiency. 3. Neurological damage: patients with neurological damage are not suitable to take vitamin B12 before a clear diagnosis is made to avoid masking the symptoms. The specific use of drugs, it is recommended that patients in the guidance of the doctor, the use of drugs in the process of other adverse reactions, the need to consult a doctor in a timely manner to avoid serious adverse reactions.