Xuefang Hu, Huiling Cheng, Shuwang He and Guangxi Zhai
Calcium is an important mineral element in the human body, which affects human life and health. 99% of calcium is found in bones and teeth, and 1% in blood, extracellular fluids and soft tissue cells called mixed calcium pools. Calcium in bones and teeth can maintain the firmness of bones and teeth and prevents various orthopaedic diseases, including osteoporosis, osteopenia, osteomalacia and rickets. Calcium in the blood, extracellular fluid and soft tissue cells can maintain the normal contraction of skeletal muscle and myocardium; maintain the permeability of biological membranes, and secretion and storage of hormones. This review summarizes the physiological function and the absorption mechanism of calcium as well as the factors affecting the calcium absorption. This paper mainly introduces the absorption mechanism of calcium factors affecting calcium absorption, the side effect of the excess of the calcium formulation and the classification of the calcium formulation. Calcium absorption is influenced by hormones, dietary ingredients, personal factors and other factors, of which hormones are the most important factor. The adverse effects of calcium overdose include cardiovascular disease, kidney stones, prostate cancer and adverse gastrointestinal events. So we should choose the right dose for calcium supplement. The classification of the calcium formulation includes inorganic calcium, organic acid calcium, calcium amino acid chelate and collagen peptide chelated calcium. At present, the most common calcium supplement in the market is inorganic calcium and organic acid calcium. Calcium peptides have the advantages of high absorption efficiency, no side effects and high solubility. So it has become a research hotspot.