How long to stop taking B vitamins depends mainly on what kind of disease is caused by the lack of B vitamins, as well as the severity of the disease, the degree of deficiency in the body and the amount in food. B vitamins are very important vitamin species in the human body and have a very important role in normal sugar, fat and protein metabolism, synthesis of various cellular enzymes, and are essential for nerve sheath synthesis. Clinical deficiency of B vitamins can lead to a variety of diseases, such as common stomatitis, peripheral neuritis, dermatitis, etc. Even the occurrence of some tumors has a correlation with B vitamin deficiency. Clinically, depending on the disease, the time to take the medication varies, such as the common megaloblastic anemia caused by vitamin B12 and folic acid deficiency, which may require B vitamins for about 3-6 months depending on the severity of the disease. The specific duration of taking B vitamins must be decided by consulting your doctor and according to your doctor’s instructions and laboratory indicators, in case you stop taking them too early or take them for too long, which is detrimental to your health.