For those who are deficient in B vitamins, a daily dose of one tablet of B vitamins is appropriate and generally not harmful. If normal people take a large dose for a long time can appear irritability, fatigue, loss of appetite and so on. Vitamin B belongs to the water-soluble vitamin preparations, in the clinical can be treated because of the lack of vitamin B caused by diseases, such as dyspepsia, eczema, chronic dermatitis, etc., this kind of people take a piece of vitamin B per day is more appropriate, usually will not be harmful. If normal people long-term, large doses can appear irritability, fatigue, loss of appetite, occasional skin flushing, itchy symptoms, and may cause yellow urination and other adverse reactions. It is contraindicated for those who are allergic to the product. It is recommended to take B vitamins under the supervision of a physician, self-medication is not recommended.