Whey products, milk minerals and dairy calcium - InnovateWithDairy ...

APPLICATIONS MONOGRAPH ■ CALCIUMMAJOR FUNCTIONS OF CALCIUM IN THE BODYCALCIUM’S ROLEIN BONE DEVELOPMENTBones serve as a basic support systemprotecting vital organs and as a reservoir forcalcium — the most abundant mineral inthe body. In fact, 99% of the body’s calciumis found in bones and teeth (the other 1% isfound in cells, blood, and other body fluids).Despite its static appearance, bone isconstantly being formed and broken down.This process, called remodeling, is theresorption (breaking down) of existing boneand deposition of new bone to replace thatwhich has been broken down. At any onetime, about 10% to 15% of bone surfacesare undergoing remodeling. A numberof interrelated hormonal, nutritional,mechanical, and genetic factorsinfluence remodeling.Resorption of old bone and formation ofnew bone are processes that continuouslyoverlap. The importance of these processesvaries at different times throughout the lifecycle. In general, from birth until aboutage 20, the bones are in a phase of activegrowth. Beginning in the 40s or later,resorption of existing bone starts to exceedformation of new bone, resulting in a netloss. Age-related bone loss is influenced byboth genetic and environmental factors.The body’s calcium status depends more onoverall nutritional factors than just calciumintake. Some nutritive factors influence thebody’s absorption of calcium, while otherfactors affect calcium retention or urinarycalcium excretion. Urinary losses of calciumare a big determinant of calcium loss.Calcium nutriture depends not only oncalcium intake, but also on numerousdietary and nondietary factors that influencecalcium metabolism. Dietary factors aidingcalcium absorption and retention include:vitamin D, lactose (which stimulatesthe intestinal absorption of calcium inlaboratory animals and in human infants),fructo-oligosaccharides, phosphorus,protein, sodium and other elements.BEYOND BONESCalcium also is important for thedevelopment of teeth. Teeth, like bones,are calcified tissue. The teeth begin to formin the first few months of fetal life and themineralization process continues into lateadolescence. An adequate intake of calcium,in addition to phosphorus, protein, fluoride,and vitamins A, C, and D, is needed forproper development of tooth structures.Although the mature tooth is metabolicallyactive, the fully eruptive adult tooth is notsignificantly subject to resorption.Outside of bones and teeth, the level ofionized calcium in the blood must bemaintained within a narrow range toperform calcium’s regulatory functions.When the diet is low in calcium, thebones release enough calcium into thebloodstream to meet the body’s needs.Although the amount of calcium outsidebones and teeth is relatively small, it isrequired for a number of basic regulatoryfunctions including:• Contraction and relaxation of muscle(including normal heart beat)• Coagulation of blood• Transmission of nerve impulses• Activation of enzyme reactions• Stimulation of hormone secretions• Integrity of intracellularcement substancesCalcium for Mature Adults51 and OlderEverybody needs calcium. But withage, one needs more to offset calciumlosses from bone and decreasedcalcium absorption. Individuals 51or over need 1,200mg of calciuma day. Though calcium can be foundin a variety of foods, leading healthexperts recommend milk and milkproducts as the preferred sourcesof calcium.2eJ.2