Calcium is the most common and abundant mineral inthe body and is found primarily in the bones and teeth. A small but absolutely essential amount of calcium is found in the blood and soft tissue. As a result ofhomeostasis, the body will take calcium from the bones if there is not enough circulating in the blood and extracellular fluid. The skeleton is constantly being absorbed and remodeled. Bone is made from calcium and phosphate combined into one crystal calledhydroxyapatite. Osteoporosis results from many factors some of which are inadequate calcium intake orabsorption along with accompanying adequate vitamin D levels, hereditary factors, lack of bone stressors(exercise) throughout ones life, and hormone function.
Lime as building material was used since prehistoric times going as far back as 7000 to 14000 BC. The first dated lime kiln dates back to 2500 BC and was found in Khafajah mesopotamia. Calcium (from Latin calx, genitive calcis, meaning "lime") was known as early as the first century when the Ancient Romans prepared lime as calcium oxide. Literature dating back to 975 AD notes that plaster of paris (calcium sulfate), is useful for setting broken bones. It was not isolated until 1808 in England when Sir Humphry Davy electrolyzed a mixture of lime and mercuric oxide. Davy was trying to isolate calcium; when he heard that Swedish chemist Jöns Jakob Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, he tried it himself. He worked with electrolysis throughout his life and also discovered/isolated sodium, potassium, magnesium, boron and barium. Calcium metal was not available in large scale until the
Non dairy sources of calcium such as legumes, leafy green vegetables, tortillas made with limestone, tofu, nuts, seeds, peas and lentils and foods where the bones are consumed, such as sardines and salmon. Lactose reduced milk. Dairy with lactase supplements. Smaller portions of dairy products as the body allows. Yogurt with live cultures and aged cheeses are sometimes better tolerated than other dairy products such as milk.
Factors that facilitate the absorption of calcium include: vitamin D and Vitamin K, sufficient hydrochloric acid in the stomach, small amounts of fat (high fat reduces the availability of calcium), exercise, magnesium, and hormones, including the parathyroid and estrogen hormones.
1- BONE FORMATION = The important minerals within bone are calcium, phosphate and magnesium. ther is a about 1kg of calcium in the adult skeleton as acomplex crystalline material with phosphate in the form of hydroxyapatite,Ca10(PO4)6(OH)2. calcium comprises 39.9% of the weight of bone minerals. bone also contain ions of magnesium, zinc, sodium,carbonate and fluride. this minerals is laid down in aorganised manner on an organic matrix, the main constituent of which is collagen. there also important non -collagen protein with in the skeleton.
The enamel and dentine of tooth contain considerable amounts of hydroxyapatite. in teeth the hydroxyapatite is present alongside a protein called keratin in place of the collegen the clacification of deciduous teeth begain by the time a foetus is about 20 weeks old and is comleted only shortly before they erupt at about 6 months.the wisdom teeth, which are the last to erupt, may not begain to calcify untill a child is between 8 and 10yearsfound in bones.
calcium is obviously required for growth because it forms an important part of bones and teeth, and is also required in much smaller amounts for the proper functioning of every cell in the body
It activates the several enzymes such as pancreatic lipase, adenosine triphosphatase and some proteolytic enzymes. It helps to absorb vitamin B12 in the ileum. It helps the absorption process by increasing the permeability of cell inem brains.
it is seen more often in premature infants than full term infants is their growth and clasification rate demand more calcium and vitamin D. rickets are delayed closure of the fontanelles, bulging or bossing of the forehead and soft and fragile bones. there may be bowing of the legs or knock -knees if there is largement of wrist knee and ankle joints. muscle develapment is poor and walking may be delayed. there may be restless and nervous irritability.
calcium requirment are also increased during pregnancy to meet the needs of a grewng fectus and during lactation to compensate for calcium secreted in the breast milk. If the mothher ‘s diet is deficient in the calcium content, the calcium from her bones will be depleted preodisposing her to fractures of the bones. Hence aequete supply of calcium is asential during regnancy and lactaton periods. bones. Hence aequete supply of calcium is asential during regnancy and lactaton periods.
Excessive intake of calcium can result in raising the blood calcium. Thereby causing by increased deposition of calciumin the soft tissues and increased excreation of calcium in urine. Infants who are given excessive does of vitamin D exhibit gastro-intestinal upset and retarded growth.
Calcium taken in food is not absorbed fully, hence, additional amounts of its intake is essential. the requirment of calcium is more in pregnancy, lactation and growth period
Doses vary from person to person. It is recommended that calcium be taken in a good multimineral supplement, although extra doses may be taken up to 1,000 mg a day.
As with many vitamins and minerals, too much as well as too little of calcium in the diet is not desirable. Excessively high intakes of calcium can interfere with the absorption of zinc, magnesium, iron, phosphorus and other nutrients. An increased intake of calcium in the diet increases requirements for magnesium, another mineral important for bone health. It has been suggested that the recent trend towards fortifying foods with extra calcium, increasing calcium but not magnesium intakes, has caused a nationwide imbalance in optimal calcium to magnesium ratios. Research studies have shown that animals fed diets deficient in magnesium develop skeletal abnormalities, including osteoporosis. When calcium in the body is too high compared to magnesium, excess calcium may be deposited in the soft tissues. This may result in calcium deposits in places such as the kidneys, the arteries and the heart.