Calcium The body of an adult normally contains about 1,500g of calcium. At least 99 percent in the skeleton where calcium salts held in a cellular matrix provide the hard structure of the bones and teeth. Obviously all of this calcium comes from the diet. Among common foods, the calcium containing protein of milk and cheese are especially valuable for growing children. Half a liter of cow’s milk contains about 0.6 g. of calcium. Most other foods contribute much smaller amounts. However, peas, beans, other vegetables and particularly cereal grains although their calcium content expressed as mg/100 g. is not impressive are frequently the chief contributors because of the large amounts eaten. By contrast, there are certain foods that are extraordinarily rich in calcium, yet which are eaten so rarely or in such small amounts that they contribute little to the regular intake.
The problem of calcium absorption is extremely complicated. There can be no clear answer that will explain why as much as 70 per cent of the calcium in the food is normally excreted in the faces. Obviously calcium absorption is not just a simple matter of the passage through the intestinal mucosa of free calcium ions, kept in solution by the benign influence of gastric juice, as many have believed. Other factors are clearly involved.
Calcium absorption may be impaired either by lack of vitamin D or by certain substances in the diet which can form insoluble salts with it. These include physic acid and unabsorbed fatty acids. Physic acid is present in the outer layers of cereal grains. Hence bread made from high extraction flour contains more physic acid than white bread. To overcome the influence of physic acid, calcium carbonate has been added to flour in
Recommended allowances are; adult’s 0.5-0.8 g. children 1 g raising 1.4 g. during adolescence; pregnancy 1.5 g lactation 2 g. Deficiency of calcium and vitamin D go hand in hand and are best considered together. Tenderness on pressure is common at many bone prominences. Titans are often manifested by corporeal spasm and facial twitching. The knee jerks may be exaggerated. Spontaneous fractures occasionally occur, independent of the pseudo-fractures described below.
Diagnosis: when the characteristic deformities are present this is easy, but in early cases it may be difficult. The early symptoms probably cannot be distinguished from those present in osteoporosis and may also be mistaken for rheumatism. Radiological examination of the bones in osteomalacia shows generalized rarefaction. In addition there may be bilateral, symmetrical pseudo-fractures at points where arteries cross the bones of the scapula, the pubic ramie and the neck or more rarely the shaft of the femur.
The clinical picture of rickets or osteomalacia is occasionally seen as a result of other diseases which condition the calcium deficiency. These diseases are of two kinds:
- The Malabsorption Syndrome: If the intestinal absorption of fat, and therefore of fat soluble vitamin D, is impaired, the body is deprived of a sufficiency of this vitamin to promote the normal absorption of calcium. At the same time the unabsorbed fatty acids form insoluble soaps with the calcium, thus further inhibiting its childhood form this may cause late rickets. In the adult secondary osteomalacia may result. Treatment should include both calcium salts and vitamin D by mouth, in the doses recommended above for primary osteomalacia, preferably taken between meals so that undigested fatty acids do not interfere with their absorption. In addition the cause of the malabsorption must receive appropriate treatment.
- Renal Disorders. In renal failure with uremia and in a variety of disorders of the kidney with disturbances in tubular function, including the
The primitive cell, the proerythroblast, is a large cell with deeply basophilic cytoplasm, no hemoglobin, and a finely reticulated nucleus containing nucleoli. From this cell, by division, and under the influence of certain harmopoietic factors, is derived the early norm oblast which is a smaller cell with denser nucleus and basophilic cytoplasm. The next stage in maturation is the development of hemoglobin as indicated by the polychromatic character of the cytoplasm. Complete maturation of the norm oblast is reached when the cell is full haemoglobinised and contains a dense and psychotic nucleus. The disappearance of the nucleus then completes the formation of the mature erythrocyte and stains faintly bluish with the Romano sky stains. With survival staining the polychromatic material appears as a fine reticulum. The mature erythrocyte is eosinophilic in staining and contains no reticular material. It is a circular biconcave disc with remarkable uniformity of size, the diameter of the great majority being. In the healthy adult only mature erythrocytes and a few reticulocytes are to be found in the peripheral blood. Nucleated red cells never appear in the peripheral blood normally. Accordingly their presence indicates excessive or abnormal blood formation or irritation of the bone marrow. An excessive number of reticulocytes may occur for the same reasons. The mega oblast, an abnormal red cell precursor, is considered on page 569.
Reflex rigidity and referred tenderness of the phenomena we associate with pain in the abdomen, the most striking is muscular rigidity. This sign is sometimes considered peculiar to inflammations in the abdomen but is in fact associated with deep pain everywhere in the body. For example, pain from sinusitis produces corresponding muscular rigidity in the face. Sometimes this reflex rigidity in the abdomen is spoken of as guarding implying that the rigid muscle overlies and protects the inflamed viscus. But the muscle concerned does not necessarily lie directly over the diseased organ. Rigidity in the abdomen usually results from peritoneal inflammation and may be present even if the original pain has disappeared. It should be sought for most carefully.
Referred tenderness There is no good phrase to describe the tenderness which may be elicited at a distance from the diseased organ. In certain diseases, as in inflammation of the gall-bladder, not only may pain be felt in a situation distant from the gallbladder but there may also be tenderness on pressure over the right lower ribs posterior which can persist after the original pain has subsided. The mechanism of this phenomenon is not clearly understood.
In a number of apparently healthy children and adolescents, and less commonly in adults, protein is excreted in the urine in variable but usually small amounts without associated disease of the kidneys. The urine formed while these individuals are recumbent is free from protein so that examination of the first specimen voided immediately on rising in the morning is normal. On the other hand urine formed while the individual is in the erect position or following exercise is found to contain protein. Tests of renal function show no abnormality.
There is evidence that the protein is due to a rise in pressure in the renal veins produced by a kinking of the inferior vane lava as it passes though the diaphragm. It has been suggested that this kinking depends upon the forward rotation of the liver and the degree of fixation of the inferior vane cave to the posterior surface of the liver. Extreme lordships while upright or recumbent will produce proteinuria in the majority of young subjects. Hyaline casts, red cells, epithelial cells and leukocytes increase in proportion to the degree of proteinuria. Proteinuria of the orthostatic type is occasionally seen in the presence of renal disease. It should be regarded as a benign condition only if careful investigations fail to reveal any other abnormality.
