Calcium nitrate salt" 5Ca(NO).NHNO·10HO. This is called calcium ammonium nitrate. Formulations lacking ammonia are also known: Ca(NO)·4HO (11.9-0-0 + 16.9 Ca) and the water-free 17-0-0 + 23.6 Ca. A liquid formulation (9-0-0 + 11 Ca) is also offered. An anhydrous, air-stable derivative is the urea complex Ca(NO)·4[OC(NH)], which has been sold as Cal-Urea. Calcium nitrate is also used to control certain plant diseases. For example, dilute calcium nitrate (and calcium chloride) sprays are used to control bitter pit and cork spot in apple trees. Calcium nitrate is used in waste water pre-conditioning for odour emission prevention. The waste water pre-conditioning is based
Calcium metabolism excretion of calcium is relatively modest (about 5 mmol/day) in comparison to what can be excreted via the feces (15 mmol/day). The plasma ionized calcium concentration is regulated within narrow limits (1.3–1.5 mmol/L). This is achieved by both the parafollicular cells of the thyroid gland, and the parathyroid glands constantly sensing (i.e. measuring) the concentration of calcium ions in the blood flowing through them. When the concentration rises the parafollicular cells of the thyroid gland increase their secretion of calcitonin (a proteinaceous hormone) into the blood. At the same time the parathyroid glands reduce their rate of parathyroid hormone (or