Posted on February 17, 2015
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Calcium
calcium containing foods
Description
Calcium is the mineral present in the largest quantity in the body about 1200g, or over 2.5lb in the average adult.
99% of it is in our bones and teeth, and bone is not static there is constant change even in an adult throughout life. It is thought that about 700g of calcium enters the bones and leaves throughout the day. Therefore in an adult the skeleton undergoes a complete renewal around once decade and in a child yearly.
Calcium is an essential raw material for this basic rebuilding although it needs other elements – particularly phosphorus, magnesium and vitamins A, C, D and E in the body to work properly.
The 1% of calcium that is in our blood, not in our bones, has different and important functions. It is essential for muscle contraction and blood clotting. Calcium also determines the strength of nerve reactions to stimuli and the metabolism of vitamin D.
Besides these functions in which it is the main component calcium also helps activate enzymes which are necessary to trigger off other body processes.
Calcium helps the body use iron – necessary for lactation and hormone functions which are necessary for parathyroid hormones to function. As with many food elements, much of our knowledge of the need for calcium is based on evidence of what happens without it.
Deficiency Effects
A lack of calcium can show up in many ways:
Facial twitching
Weak feeling muscles – cramp and other muscles – nerve symptoms are often signs of inadequate calcium.
Lack of calcium in children, in extreme cases, results in rickets. Common in British cities until WW2.
Cities were affected more, it is thought, because children there also had poor access to sunlight – vitamin D – which aids calcium absorption, and they often had poorer diets in general.
In older people a lack of calcium causes osteoporosis, brittle bones due to a lack of protein and calcium.
The relationship between calcium status and hormones is close and shows in women after menopause, where the discontinuance of oestrogen production by the body goes hand in hand with an increase in osteoporosis.
However neither extra calcium nor extra oestrogen hormones ha been shown to arrest osteoporosis linked with aging. While a shortage of vitamin D due to lack of sunlight on the skin. A lack of physical activity causing increased calcium loss and the need for good general nutrition – could be the key.
Dosage and Toxicity
People cannot trust there body to absorb calcium more efficiently if supplies are reduced, they must make sure they get ample amounts. The more used we are to a high calcium diet, the less likely we are to adapt our absorption to get enough frm an unfamiliar low calcium diet. Older adults in any case absorb calcium less efficiently.
The National Research Council recommends 800mg would maintain the necessary balance. In pregnancy the RDA intake increases to 1200mg.
The effect of an excessive intake of calcium and vitamin D can cause hypercalcemia which can result in bone calcification, it also interferes with nervous and muscular function.
Blood plasma coagulation does not occur with an excess of calcium.
To little magnesium results in calcium accumulation in the muscles and heart and also in the kidneys causing kidney stones.
Good Dietary Sources
Hard cheese, Milk, Natural yoghurt, Sardines, Black molasses, Kelp and other seaweeds, Alfalfa, Chammomile, Dandelion. Plantain, Cleavers, Nettle, Confrey, Borage, Croneswort, Oats, Parsley, Linseeds, Shepards purse, Red clover, Raspberry leaf, Cress and Thyme.
