In fact, as long as we take vitamin B complex in moderation according to the doctor's advice and instructions, it will have a gain effect on the human body, but once we take it for a long time, it will have side effects and affect our health. The first is that taking a large amount of vitamin B complex will cause symptoms such as irritability, anxiety, fatigue, loss of appetite and malaise, which is mental. On our body, there may be skin flushing or even symptoms, and urine will become abnormal. For example, urine will show yellow instead of normal color. The above are the side effects of taking vitamin B complex. The reason is that we rely too much on health care products and eat too much. We have learned about the side effects of taking vitamin B complex. Although there are side effects, we can't deny that vitamin B complex still has strong efficacy and function on human body. It can treat acne, seborrheic dermatitis and so on, so we still need it, and we can use it after consulting a doctor.