Being an essential element, calcium is obtained through dietary sources, the majority of which comes from dairy products. The three most significant mechanisms controlling calcium use within the body are intestinal absorption, renal absorption and bone turnover, which is controlled predominantly by hormones and their corresponding receptors in the gut, kidneys and bones respectively. This allows for calcium use throughout the body, namely in bone growth, cellular signalling, blood clotting, muscle contraction and neuron function.[16][17]