666 X. VITAMINS D 



is kno^^^l to exist. Nicolaysen and Eeg-Larsen^ also refuted these claims 

 by the facts, repeatedly proved, that the absorption of phosphate is rapid 

 and complete in vitamin D deficiency, pro\dded no calcium salts are pres- 

 ent. Moreover, it is pointed out' that no attention was paid to oxygen 

 supply in Heymann's experiments, while the mucous membrane of the 

 gut has been shoAMi to be extremely sensitive to oxygen deprivation.-^^ 



Rominger,^^'' in a review based upon earlier publications,-*^--*^ expressed 

 the view that vitamin D acts primarily upon the phosphate metabolism of 

 children. McGowan-*'^ and McGowan et al.}^^ postulated that vitamin D 

 acts by setting free inorganic phosphorus from the body lipids, the relative 

 deficiency of which is regarded as the essential cause of rickets. However, 

 there was no proof to substantiate the conjecture. Nicolaysen-*^ also 

 observed a decrease of the organic phosphorus + phosphocreatine fraction 

 in the muscles, and of the inorganic phosphorus in the liver and kidneys of 

 rachitic rats on a vitamin D-free diet containing calcium and phosphorus. 

 A reduction was noted in the phospholipids and protein-phosphorus in 

 the livers of these rachitic rats, but not in the muscles. This condition 

 was corrected by vitamin D therapy, and the addition of phosphate without 

 vitamin D was able to effect the same change. This investigator' '-^^ 

 is of the opinion that phosphorus starvation is responsible for the afore- 

 mentioned condition, and that vitamin D is not the factor controlling the 

 balance between the different forms of phosphorus in the organism. 



In the well-controlled experiments of Rapoport and Guest, 2^" -^^^ it was 

 observed that, in the case of rats rendered rachitic by a diet high in cal- 

 cium and low in phosphorus, an initial decrease in the inorganic phos- 

 phorus and adenosinetriphosphate (ATP) of the blood cells was followed 

 by a reduction of diphosphoglycerate in the blood. When healing of the 

 rickets was induced by a minimum dose of vitamin D, by the addition of 

 phosphate to the diet, or by fasting, these components progressively in- 

 creased in the blood cells in the reverse order, i.e., first diphosphoglycerate, 

 then ATP, and inorganic phosphate. Diglycerophosphate was believed 



283 R. B. Fisher and D. B. Parsons, J. Physiol, 110, 36-46 (1949). 

 ''s^E. Rominger, Erqeh. Vitnmin-u. Hormonforsch., 2, 104-159 (1939). 



286 E. Rominger, H. Mever, and C. Bomskov, Z. ges. exptl. Med., 73, 343-381 (1930); 

 Klin. Wochschr., 9, 1391-1394 (li)30). 



28« E. Rominger, H. Mever, and C. Bomskov, Z. qea. ex-ptl. Med., 7S, 259-271, 272-286 

 (1931). 



287 J. P. McGowan, Biochem. J., 27, 943-950 (1933). 



^88 J. P. McGowan, I. J. Cunningham, and D. W. Aiichinachie, Biochem. ./., 25, 1295- 

 1303(1931). 



288 R. Nicolaysen, Biochem. J., 30, 1329-1337 (1936). 



290 S. Rapoport and G. M. Guest, J. Biol. Chem., 126, 749-761 (1938). 



291 G. M. Guest and S. Rapoport, Am. J. Diseases Children, 58, 1072-1089 (1939). 



