When the human body is seriously deficient in calcium, there can be the following symptoms: first, lead to epileptic seizures, severe calcium deficiency can induce epilepsy, there can be twitching and spasms of the hands and feet, and in severe cases, there can be spasms of the facial muscles. Second, there can be symptoms of numbness and tingling of the lips as well as the tongue, hands and feet. Third, there can be nerve percussion signs on the face, when the facial nerve is percussed, there can be twitching of the corners of the mouth as well as the eyelids. Fourth, mental symptoms, severe calcium deficiency can lead to anxiety, depression and drowsiness and other mental symptoms. Fifth, there can be skin changes, such as dry, scaly skin, brittle nails and thickened hair. Sixth, it can lead to calcification of intracranial basal ganglia, which can lead to secondary convulsions and cataracts. Therefore, patients with hypocalcemia should be treated with calcium supplementation at an early stage to avoid serious complications.