Calcium is the most represented mineral in the human body. 99% are contained in the bones and teeth. Calcium becomes effective only in connection with magnesium and phosphor, as well as with the vitamins A, C and D. Calcium supports the blood clotting and the regulation of the pH-value in the blood. Additionally, it plays an important role in the muscle development, the muscle contraction and the transmission of nerve impulses. If calcium combines with magnesium, it keeps the circulation and the heart healthy. We frequently find calcium in milk and dairy products. As there often is a shortage of calcium in the industrialised countries, the intake of food supplements with calcium is important not only for athletes.