THE " RETROGRADE CIRCULATION OF CALCIUM " 



IN THE HUMAN BODY 



G. DELGADO PALACIOS 

 (Biochemical Laboratory of the University of Caracas, Venezuela) 



(Received for publication, December ii, 1914)- 



Introduction. Calcium is an essential dement in the biochem- 

 ical Constitution of the human body, through which it circulates 

 constantly. In various forms, calcium enters the organism with 

 food and potable water, and leaves it in urine and feces. Other ex- 

 cretions normally contain traces of calcium but, under pathological 

 conditions, may carry much larger quantities, e. g., the Sputum in 

 pneumonia and pulmonary tuberculosis, as stated by Loeper and 

 Bechamp ( i ) . Ingested calcium is partly absorbed in the stomach 

 and Upper portion of the small intestine. Most of the ingested cal- 

 cium usually passes unahsorhed along the intestinal tract and is elim- 

 inated in the feces. Absorbed calcium is excreted along two differ- 

 ent Channels, some being ejected by the kidney, some by the lower 

 portions of the small intestine. The foregoing Statements indicate 

 the normal circulation of calcium in the human body, as established 

 by the successive investigations of Forster, Voit, Müller, Neubauer, 

 Bertram, Renvall, and others. The relative quantities of calcium 

 involved in the different phases of this circulation vary considerably 

 with the physiological State, the age, and peculiarities of the indi- 

 vidual but, above all, with the quality and quantity of the food. 



Calcium is eliminated in the urine in combination principally with 

 phosphoric acid, also with sulfuric, carbonic, oxalic and uric acids; 

 that is to say, with acids which form with it slightly soluble Com- 

 pounds (2). The daily quantities of urinary calcium vary from 

 about 0.15 gm. to 0.50 gm., according to different authors. The 

 fecal calcium, that is to say, the difference between the ingested 

 and the urinary calcium, also varies greatly in quantity, under both 

 normal and pathological condition. 



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