Three-month-old baby calcium deficiency symptoms are mainly manifested as excessive sweating, occipital baldness, irritability, hand and foot twitching, cranial softening and other symptoms. 1. Excessive sweating: when a three-month-old baby lacks calcium, the body’s calcium and phosphorus metabolism is disorganized, which can show the symptoms of excessive sweating. 2. Occipital baldness: mainly manifested in the head and pillow contact area of hair sparse or no hair. 3. Restlessness: Calcium deficiency can cause increased nerve excitability, manifesting as restlessness. 4. Convulsions of hands and feet: in case of severe calcium deficiency, it can be manifested as convulsions of hands and feet, laryngeal spasms, or generalized epileptic seizures accompanied by facial muscle spasms and other symptoms. 5. Cranial softening: when the symptoms of calcium deficiency are severe, there can be cranial softening, with the fingertips a little hard pressure on the back of the head and the back of the head position, it will present a ping-pong ball feeling. Calcium deficiency in three-month-old babies can also appear other symptoms, it is recommended to go to the hospital in a timely manner, combined with laboratory and imaging tests, a clear diagnosis, timely treatment under the guidance of the doctor.