There is no clear definition of calcium loss. People generally refer to adulthood, when one enters a period of negative calcium homeostasis, i.e., decreased absorption and increased excretion of calcium. This tends to lead to symptoms of calcium deficiency. Symptoms of calcium deficiency vary among different groups of people. 1. Children: irritable and fidgety during the day; not easy to fall asleep at night, easy to wake up and cry after falling asleep, excessive sweating; paroxysmal abdominal pain, diarrhea, cramps, etc.; severe cases will appear “X”, “O” shaped legs; anorexia and partiality in eating; irritable during the day, fidgety; delayed intellectual development, and a lack of calcium in the brain, Fidgety; late intellectual development, late speech, late learning to walk; late and slow growth of teeth, sparse and uneven arrangement. 2. Adolescents: daily fatigue, irritability, difficulty in concentrating and feeling easily exhausted; often feel obvious growing pains, leg weakness and cramps and other discomforts; show anorexia and partiality in eating; reduced immunity, easy to catch a cold and other symptoms. 3. Youth: There are no typical symptoms of calcium deficiency in youth. So it is often ignored and not easy to notice. When there is frequent fatigue, allergies and colds, back pain, cramps in the hands and legs, etc., you need to be vigilant to see if calcium deficiency. 4. Pregnant women: During pregnancy, the daily demand for calcium increases greatly, so there is no special calcium supplementation, and calcium deficiency is easy to occur. Common symptoms are numbness and weakness of the limbs, easy to cramp; lumbago, back pain, joint pain and other symptoms. 5. Elderly people: more prone to calcium deficiency. Symptoms often accompanied by loose teeth, fall out; obvious hunchback, height reduction: geriatric skin disease itching; cervical spine, lumbar spine, heel pain; quality of sleep decline, insomnia, not easy to fall asleep; loss of appetite, constipation, peptic ulcers; emotional easily produce irritability, and irritability. If you are experiencing any of these symptoms, it is recommended that you seek medical attention. Test the blood calcium level or bone density and take calcium supplements under the guidance of your doctor.