Calcium carbonate is inorganic calcium, which can be absorbed by the body by decomposing into calcium ions. Calcium plays an important role in the human body, not only in the formation of bones, but also in regulating the excitability of the nervous system and in stabilizing the balance of body fluids. When calcium carbonate enters the body, it can be broken down into calcium ions, which are absorbed in the upper part of the small intestine and sent throughout the body with the blood. However, in the process of calcium carbonate absorption, the participation of vitamin D is also required. Under normal circumstances, vitamin D is present under the epidermis as inactive osteopontin, which is activated by ultraviolet radiation and then undergoes 2 enzymatic reactions in the liver and kidneys, which in turn form 1,25-bishydroxyvitamin D and promote calcium absorption into the blood. Calcium deficiency can lead to rickets and osteomalacia in children and reduced height, loose teeth and back pain in adults. Therefore, it is important to seek medical attention to identify calcium deficiency. If diagnosed, you can take calcium supplements under the guidance of your doctor and get more sunlight in your life to promote calcium absorption.