Symptoms of vitamin D deficiency include changes in mental state and changes in the bones of the body. 1. Changes in mental state: When a child has a vitamin D deficiency, most of the early symptoms include excessive sweating, night terrors, irritability and other symptoms of increased nervous system excitability, as well as occipital baldness and thinning hair. 2. Skeletal changes: if vitamin D deficiency is not detected in time or without timely intervention and treatment, the condition will gradually aggravate and skeletal changes will occur, such as square cranium, bracelets and anklets, chicken chest, X-shaped legs, O-shaped legs, etc.; when vitamin D deficiency is severe and causes hypocalcemia, convulsive symptoms such as convulsive seizures of the hands and feet and laryngeal spasms may occur. Therefore, when the child has symptoms of vitamin D deficiency, it is necessary to take the child to the hospital pediatrics in a timely manner, according to the condition of the targeted intervention treatment.