Is Calcium Store in the Body

Is Calcium Stored in the Body?


                In the May issue of Nutrition and Dental Health, under Nutritional Notes, we stated that “minerals in the body are stored chiefly in the bones and teeth.”

Soon after the journal was out, a dentist called our office and asked if it were true that minerals were store in the body in the true sense of the word “store.” The definition for store is, “that which is collected and stored against future use.”

He asked if it were true that the deposits of minerals in the bones and teeth would be available for future use if the body requirements needed more minerals than were provided in the dietary.

Minerals in Bone Can be Used

This brings up a question that has not generally been considered. It is common to see the bones and teeth referred to as storage places for calcium and phosphorus, but there is a question as to whether the bony skeleton acts, both as a support for the soft tissues and a mineral store house future needs.

Dr. Abraham Cantarow in his book “Calcium Metabolism and Calcium Therapy” states: Bone resorption and deposition are going on in all bones constantly, both processes being more rapid in regions of active growth, irrespective of anatomical structure.

The regions of most active growth and, consequently, those most susceptible to decalcification under the influence of parathyroid hormone, are: the spongy bone of the metaphyses, especially in ling tubular bones; the costochondral junctions; the cortices of the shafts of bones, particularly near the epiphyseal plates; the bones of the skull and lower jaw.

When the rate of bone resorption or deposition is increased, it is increased in all bones but, since in regions of less active bone growth these processes go on more slowly under normal conditions, a relatively great stimulus is required to produce a considerable degree of resorption.

For these reasons the skeletons of actively growing young animals are more susceptible to the decalcifying influence of parathyroid extract than are those of adult animals.

All of the recent chemical, histological and clinical studies in this connection have demonstrated the facility with which the mineral constituents of the skeleton can be mobilized under physiological and pathological constituents. Our former conception of the metabolic significance of the bony skeleton must be radically revised; it unquestionably represents a storehouse of readily available calcium and phosphorus, capable of ready mobilizations upon demand. Its relation to calcium phosphate metabolism is analogous to that of the glycogen store of the liver to carbohydrate metabolism.” Thus it would appear that it is correct to refer to bones as a storage place for minerals.

The body normally receives its calcium supply from the injested foods. The most readily available calcium is found in milk. Investigators have found however that the calcium of vegetables is well utilized by man.

Calcium is absorbed into the blood stream from the small intestine. The blood normally carries 10 mgs. of calcium per 100 CC of blood. Blood calcium is found almost entirely in the blood serum. The blood stream carries this mineral to various parts of the body where it is utilized by many tissues.

Bone is not the only substance in the body for which calcium is necessary. The relation of calcium to the  normal calcification of bone is obvious. The physiologic and chemical process involved in ossification are not clearly understood. Calcium exists in the bone as di-calcium phosphate (83 to 90%), as di-calcium phosphate (9 to 13%). Dr. Watt explains that the deposition of calcium salts in the bone matrix is brought about by a secretion of the osteoblasts rather than by a mere precipitation.

Cell life is dependent upon an interchange of fluids. Nutrients must enter the cell and waste materials pass out. For this function calcium is indispensible. Sodium hastens cell osmosis and calcium inhibits. Therefore a normal balance of cellular activity depends upon sufficient calcium.

Blood also Needs Calcium

For the normal coagulation of blood, calcium is necessary. In case of bleeders it is often helpful to prescribe large doses of calcium salts before an operation is performed. Also in cases of accidental  injury where bleeding is difficult to control, the oral and intravenous injections of calcium salts is of value.

Calcium exerts an influence on nerve tissue similar to its action in the cell. Sodium excites nerve impulses and calcium inhibits. Calcium is necessary for the passage of the nerve impulse from nerve to muscle across the myoneural junction. The inhibitory action of calcium is also exerted on muscle irritability and is often used in the control of excitability in both nerves and muscles.

The parathyroid glands control calcium metabolism in the body. An upset in the function of the glands causes serious bodily disturbances. The removal of the gland causes a diminished calcium content of the blood and urinary excretion. An over activity of the gland causes an increase in blood calcium, a depletion of calcium in the bones, and an increased urinary excretion.

Vitamin D is intimately associated with calcium metabolism. It is the fixation factor in the body. The exact action of the Vitamins is unknown but it is believed that it may increase absorption of the mineral or it may influence the action of the parathyroid gland, or both. It is known however that Vitamin D is necessary to normal utilization of calcium and its lack causes serious upsets in general systemic health.