Significant vitamin A deficiency may cause hair loss, but hair loss may not necessarily be caused by a vitamin deficiency. Hair loss due to massive vitamin A deficiency is mild and is a normal metabolism, and generally does not require treatment. The causes of pathological hair loss include mental stress, endocrine disorders, skin diseases, neurological factors, chronic infectious diseases, etc. To treat hair loss, we must first clarify the cause and then carry out targeted treatment, for example, hair loss caused by mental factors and drug effects can basically be improved after addressing mental stress, stopping or changing medication. Hair loss caused by genetic factors or endocrine disorders can be controlled by taking drugs under the guidance of a doctor, but basically cannot be completely solved. Seborrheic alopecia caused by irregular diet, work and rest, etc. requires a combination of medication and behavioral adjustment. If the hair loss is very severe, hair can also be restored to thickness by hair transplantation. Therefore, if you lose a lot of hair for a long time, you must go to the hospital to find out the cause in time, and do not blindly take vitamin supplements, medications or use hair growth agents, so as not to delay the condition and make the symptoms of hair loss more serious, or even cause excessive mental stress and lead to certain psychological diseases.