Symptoms of calcium deficiency vary with individuals, age and so on. Weakness, cramps, and developmental delays may occur. People are advised to go to regular hospitals for checkups and systematic treatment after a clear diagnosis. Adults with calcium deficiency will experience fatigue, poor mental performance, back pain and other uncomfortable symptoms. Pregnant women are prone to cramps and other symptoms. Elderly people with calcium deficiency are prone to lumbar spine and knee joint pain, and in severe cases, hunchback and irritability. When children are deficient in calcium, it will lead to sleeplessness, easy to wake up, delayed bone development and other uncomfortable symptoms. People should not take medication on their own when they are deficient in calcium, and it is recommended that they take calcium tablets (such as calcium carbonate D3 tablets) under the guidance of a doctor.