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Minerals - Calcium

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Calcium constitutes approximately 2% (by weight) of the adult human body, with the overwhelming proportion of total body calcium in the structure of the teeth and bones.

Calcium also plays an important metabolic role as a cofactor to adenosine triphosphate (ATP), which is instrumental in the release of energy for muscular contractions. It acts as an essential cofactor in various enzymatic conversions which occur during blood clotting. It is also essential for nerve transmission and the release of neurotransmitters at neuromuscular junctions.

Calcium is instrumental in ion permeability across membranes, influences the effects of protein hormones, is necessary for proper myocardial function, and helps to preserve the integrity of intracellular cement substances.

Scientific research has not conclusively shown calcium deficiency to be the direct cause of any specific condition. However, several clinical disorders such as rickets, osteomalacia, osteoporosis, and scurvy, have been linked to abnormalities of calcium in structural bone. While conclusive evidence is pending, tetany and hypertension have also been cited as possible symptoms of calcium deficiency.


Calcium phosphate constitutes the bulk of inorganic matrix of bone. It is deposited within the soft, fibrous organic matrix as hydroxyapatite, adding to the bone's structural rigidity.

Calcium is also one of the major mineral constituents of tooth enamel and dentin, both of which serve as rigid exterior protection for the sensitive interior pulp of the tooth. The vast majority of calcium absorption takes place via active transport in the duodenum and is greatly facilitated by the action of vitamin D, lactose, and high levels of dietary protein.

Vitamin D deficient diets, diets high in fat, and High Fiber Diets have the reputed effect of curtailing calcium absorption, which is only 10 to 30% efficient under usual physiological conditions.

When serum blood levels of calcium fall, parathyroid hormone is secreted. This stimulates increased absorption of calcium from the intestine and resorption of calcium from the bone. However, high blood calcium levels trigger the release of the hormone calcitonin, which induces renal excretion of calcium and inhibits further resorption from the bone. The mutuality of these two hormones allows a feedback control of calcium levels in blood serum.

Consumption of dairy products, one of the primary food sources of calcium, can decrease absorption of most tetracycline antibiotics, with the notable exceptions of deoxycycline and minocycline.

Neomycin, cycloserine, erythromycin, sulfonamides, tetracyclines, penicillin, isoniazid, and para-aminosalicylic acid reportedly decrease calcium absorption to some degree.

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Calcium has been used in the management of uremic bone disease, a disorder in which chronic renal failure produces abnormally high serum phosphate levels and, reciprocally, low serum calcium levels.

It is thought that unexplained calcium deficiencies may be related to excessive magnesium depletion. Calcium supplementation helps to prevent the excessive resorption of calcium from the bones. Experimentation has shown that adequate calcium intake can prevent and, on occasion, reverse resorption of bone in human periodontal disease.

Calcium and vitamin D supplements are effective in the treatment of osteomalacia; vitamin D promotes increased calcium absorption within the duodenum.

Although not a proven cure, increased calcium and vitamin D intake is beneficial for the elderly with osteoporosis, as it counteracts the high rate of calcium efflux characteristic of this disease. In conjunction with vitamin D, calcium is effective in alleviating symptoms of vitamin D-dependent rickets.


Although excessive calcium intake has not been shown to be toxic, an extremely high intake of calcium in conjunction with a high intake of vitamin D can induce hypercalcemia. This condition can result in excessive calcification of bone and soft tissue (e.g., the kidney), or in the formation of kidney stones.


RDA for male adults: 1,000 mg

RDA for female adults 800 mg

RDA for children 7 to 10 years 500 mg.

RDA for infants: 275 mg.

RDA for Pregnant and Lactating Women 1,000 mg

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· Artichoke · Beet greens

· Broccoli · Beans (dried)

· Cheese · Collard greens

· Ice cream · Kale

· Milk · Okra

· Orange sherbet · Parsnip

· Rhubarb · Rutabaga

· Salmon · Sardines

· Spinach · Swiss chard

· Tangerine · Turnip greens

· Watercress

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Calcium Deficiency Symptoms In Bones

· Early stage symptoms in bones:

· Pain in the joints

· Brittleness of bones

· Bones ache on exertion

· Retarded bone and tooth mineralization

· Fragile bones

· Osteomalacia

· Rickets

· Stunted growth

· Osteoporosis

Symptoms of Deficiency of Blood Calcium:

· Over susceptible excitability of nerves and muscles

· Loss of muscle contraction ability, including the heart muscle. Also loss of ability of the muscles to relax

· Pain in the feet making walking painful or impossible

· Loss of integrity of the cement-like substances that hold body cells together

· Incorrect functioning of cell membranes

· Schizophrenia in high histamine types (histadelics)

· Reduced control of blood cholesterol

· Becomes difficult to hold objects

· Muscles lose tone and become flaccid

· Unbalanced hormone release

· Poor lactation of nursing mothers

· Face twitches

· Poor blood clotting

· Irritability

· High blood pressure

· Nervousness


· Extra calcium decreases zinc absorption if taken at the same time as a zinc supplement.

· Smoking decreases calcium absorption as the cadmium in cigarette smoke is a calcium antagonist.

· High protein diets (120 grams or more per day) stimulate bone calcium resorption and encourage long term bone loss. To avoid such a loss reduce your consumption of phosphorus rich meats and soft drinks, and eat more fruits, vegetables, grains and dairy products.

· The more indigestible the form of protein we consume the more apt we are to have a calcium deficiency.

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