Alopecia areata is a general term for hair growth disorders due to various causes. Clinically pathological alopecia areata mainly includes baldness that occurs in localized hair areas, alopecia totalis and alopecia universalis that develop from baldness, and androgenetic alopecia due to increased concentration of dihydrotestosterone in the scalp, of which only some types of alopecia have positive effects with oral vitamins. Physiologically, the cycle of hair in the hair follicle from neonatal to shedding is usually about 40 months. During this period, the hair is in the anagen phase for the first 36 months, followed by a 3-4 week regression period before shedding into a 3-month resting phase, during which approximately 80% of the hair is normally in the anagen phase, thus maintaining a normal hair mass. Normal people physiologically shed less than 100 hairs per day and have an equal amount of new hair. This kind of hair loss is most easily detected during the seasons and climate change, and no special treatment is needed. Androgenetic alopecia is clearly dominant and can occur in both men and women. It is caused by the atrophy of scalp hair follicles and shortening of the hair growth period in individuals with genetic background under the effect of excessive dihydrotestosterone, which leads to a decrease in the number of hair in the anagen phase and an increase in the ratio of resting hair. There is no evidence that oral vitamins are effective for this type of alopecia. However, it should be noted that because the cause of baldness is complex and may be related to genetics, emotional stress, endocrine disorders, autoimmunity, etc.; the disease may develop into refractory alopecia totalis and alopecia universalis when the disease is prolonged, so if the area of hair loss continues to increase, it is necessary to actively investigate the suspected causes on the basis of oral vitamins Therefore, if the hair loss area continues to grow, we need to actively investigate the suspected causes and give symptomatic treatment based on oral vitamins.