Ten-year-old children can eat vitamin B12 if they are deficient in vitamin B12. Vitamin B12 is involved in the production of bone marrow red blood cells, preventing pernicious anemia, preventing nerve damage, can increase the utilization of folic acid, promote the metabolism of fats, proteins, carbohydrates, ten-year-old children can eat vitamin B12. Lack of vitamin B12 can cause menstrual irregularities, pernicious anemia, nausea, loss of appetite, bleeding gums, headaches, nerve degeneration. Ten year old children who are deficient in vitamin B12 should be supplemented promptly. If medication is needed, it is recommended to use medication under the guidance of a doctor, not blindly self-medication to avoid adverse effects.