Calcium carbonate equilibrium pressure must exceed total atmospheric pressure of 101 kPa, which happens at 898 °C. Calcium carbonate is poorly soluble in pure water (47 mg/L at normal atmospheric CO partial pressure as shown below). The equilibrium of its solution is given by the equation (with dissolved calcium carbonate on the right): where the solubility product for [Ca] [CO] is given as anywhere from "K" = 3.7×10 to "K" = 8.7×10 at 25 °C, depending upon the data source. What the equation means is that the product of molar concentration of calcium ions (moles of dissolved Ca per liter of solution)
Calcium metabolism dairy product and eggs, as well as in tinned fish products. The calcium contained in vegetable matter is often complexed with phytates, oxalates, citrate and other organic acids, such as the long-chained fatty acids (e.g. palmitic acid), with which calcium binds to form insoluble calcium soaps. Although calcium flow to and from the bone is neutral, about 5–10 mmol is turned over a day. Bone serves as an important storage point for calcium, as it contains 99% of the total body calcium. Calcium release from bone is regulated by parathyroid hormone in conjunction with calcitriol manufactured in the kidney under