Calcium affects on vascular endpoints

Calcium is one of the most abundant minerals in the body and its metabolism is one of the basic biologic processes in humans. Although historically linked primarily to bone structural development and maintenance, it is now recognized as a key aspect of many physiologic pathways necessary for optimum health including the cardiovascular, neurological, hormonal, renal, and gastrointestinal systems. Calcium serves as a cofactor for many extracellular enzymes, most notably the enzymes of the coagulation cascade, and as a source of calcium ions that function as signaling molecules for a great diversity of intracellular processes. These processes include automaticity of nerve and muscle; contraction of cardiac, skeletal, and smooth muscle; neurotransmitter release; and various forms of endocrine and exocrine secretion. Our review will describe the biology and basic physiology of calcium metabolism in humans, the present status of recommendations for intake and supplementation, the traditional role of calcium for optimum maintenance of the skeletal system, and then discuss in detail the relevance of calcium in cardiovascular health as well as several cardiac and vascular disease states.The body of the average adult contains about 1000 gram of calcium of which 99% is located in the mineral phase of bone as hydroxyapatite crystals [Ca10 (PO4)6(OH)2]. These crystals play a key role in the mechanical weight-bearing properties of bone, serves as a source of calcium to support a number of calcium-dependent biological systems and to maintain blood ionized calcium within normal range. The remaining 1% of total body calcium is located in the blood, extracellular fluid and soft tissues. Of the total calcium in blood, the ionized fraction (45%) is the biologically functional portion and can be measured clinically. Most clinical laboratories report total serum concentrations. Forty-five percent of the total calcium in blood is bound to plasma, proteins notably albumin and up to 10% is