Calcium and Magnesium contribute to normal muscle function and are needed for the maintenance of normal bones and teeth. Zinc contributes to the maintenance of normal bones. Calcium is vital for healthy bones and teeth, blood clotting and glandular secretion and for efficient functioning of the muscles, nerves, heart and immune system. Magnesium is needed in over 300 metabolic reactions, including those involved in the management of energy, the formation of bones, proteins and cell replication. It is needed for enzyme function and the tissues with the highest levels are those with the highest metabolic activity like brain, liver, kidneys and heart. Magnesium blocks the entry of calcium into smooth muscle cells and heart muscle cells regulating their contraction.