Calcium homeostasis is the process by which the body maintains stable levels of calcium in the blood and tissues. This balance is crucial for various bodily functions, including muscle contraction, nerve transmission, and blood clotting. The body regulates calcium levels through hormones, primarily parathyroid hormone (PTH) and calcitonin, which control calcium release from bones, absorption in the intestines, and excretion by the kidneys. When calcium levels drop, PTH is released, stimulating the release of calcium from bones and increasing absorption in the intestines. Conversely, when calcium levels are high, calcitonin is secreted to lower calcium levels by promoting its storage in bones and increasing excretion through the kidneys. This intricate system ensures that calcium levels remain within a narrow range, essential for overall health.