Vitamin B12 is one of the B vitamins, mostly found in meat, animal offal and aquatic products, usually vegetarians are more prone to vitamin B12 deficiency; in addition, the absorption of vitamin B12 will be affected in people with gastrointestinal dysfunction, frequent alcohol drinkers, diabetics and gastrectomized people, thus leading to vitamin B12 deficiency, then vitamin B12 supplementation is needed. anemic people and neuritis patients also If patients have the following clinical symptoms of vitamin B12 deficiency, prompt supplementation is recommended: 1. mental fatigue: vitamin B12 is an important component in the production of red blood cells, which have the role of transporting oxygen, and if the cells lack oxygen, the body will feel mentally fatigued; 2. jaundice: vitamin B12 deficiency may make red blood cells more prone to rupture, thus releasing bilirubin, causing the patient to develop jaundice, which manifests as yellow staining of the skin, iris, etc.; 3. Other symptoms: vitamin B12 deficiency may cause the patient to lose the papillae of the tongue, thus losing the sense of taste. In addition, vitamin B12 deficiency may also cause symptoms such as numbness in the limbs, poor balance, and memory loss.