Calcium metabolism Calcium metabolism Calcium metabolism refers to the movements and regulation of calcium ions (Ca) "in" and "out" of various body compartments, such as the gastrointestinal tract, the blood plasma, the extracellular and intracellular fluids, and bone tissue. An important aspect of calcium metabolism is plasma calcium homeostasis, the regulation of calcium ions in the blood plasma within narrow limits. In this process, bone tissue acts as a calcium storage center for deposits and withdrawals as needed by the blood, via continual bone remodeling. Derangement of this mechanism leads to hypercalcemia or hypocalcemia, both of which can have consequences for health.
Calcium coating in moist air, but below 30% relative humidity it may be stored indefinitely at room temperature. Besides the simple oxide CaO, the peroxide CaO can be made by direct oxidation of calcium metal under a high pressure of oxygen, and there is some evidence for a yellow superoxide Ca(O). Calcium hydroxide, Ca(OH), is a strong base, though it is not as strong as the hydroxides of strontium, barium or the alkali metals. All four dihalides of calcium are known. Calcium carbonate (CaCO) and calcium sulfate (CaSO) are particularly abundant minerals. Like strontium and barium, as well as the alkali