Low hair may be caused by the lack of vitamin B, vitamin D, etc. It may also be caused by heredity, disease and other factors. Patients had better go to the hospital for examination, to clarify the cause of the disease and then symptomatic treatment. 1. Lack of vitamin B: Vitamin B has the role of promoting scalp metabolism. If the lack of seborrheic dermatitis may occur, resulting in the symptoms of low hair, so you can properly supplement vitamin B, so as to improve the symptoms of low hair. 2. Lack of vitamin D: Vitamin D can maintain the normal function of hair follicles, if the lack of vitamin D may make the hair follicle oil secretion, thus affecting the normal function of hair follicles. 3. Genetic factors: If there are people with low hair in the close family, then it may also be due to heredity, and this condition generally cannot be treated. 4. Disease factors: abnormalities in the pituitary gland, thyroid gland, and gonads may cause the hair follicles to be inhibited, leading to hair thinning. It is recommended to pay more attention to head hygiene to avoid clogging of scalp follicles. In serious cases, go to the hospital in time to see a doctor to clarify the cause of the disease, under the guidance of the doctor to treat the symptoms.