Hair loss may be caused by nutritional deficiencies, seborrheic dermatitis, vitamin D deficiency and other factors. 1. Nutritional deficiencies: children long time partiality picky eating, the body lack of various elements, such as zinc, iron, etc., will lead to more hair loss, may also be accompanied by body thinning, hair growth is too slow and other manifestations. 2. Seborrheic dermatitis: usually associated with fungal infections, can lead to damage to the hair follicles in the scalp area, which will lead to more hair loss, dandruff, there may also be mild itching. 3. Vitamin D deficiency: when a child is deficient in vitamin D, it can also lead to thinning hair and more hair loss, which may be accompanied by more than crying at night, leg cramps and other abnormal manifestations. If your child has a lot of hair loss and other abnormalities, it is recommended that you seek medical attention in a timely manner for examination and treatment to avoid adverse effects.