226 



VITAMIN D GROUP 



report that the first detectable signs of rickets in calves is a decrease in the 

 level of inorganic phosphorus in the serum. The same investigators also 

 found a low calcium content of the serum of their animals which was ac- 

 companied in some cases by tetany. Previously, Steenbock and associates-" 

 had observed tetany in ricketic pups. The same laboratory has also found 

 low calcium and low phosphorus in the serum of chicks^^ and low phosphorus 

 in swine-^ during rickets. In the later case, no calcium studies were reported, 

 but Loeffel et al}^ observed low calcium and low inorganic phosphorus in 

 the sera from their ricketic pigs. 



When rickets is produced in rodents by means of low phosphorus diets, 

 the phosphorus of the serum is, as expected, considerably below normal. If 



TABLE X 



Effect of Rickets in Pups on Calcium and Phosphorus in Serum 



AND ON Femur Ash^" 



the calcium in the diet is high,^"^ the serum calcium is either normal or 

 slightly elevated. The rat, for instance, never develops tetany on this type 

 of diet. 



4. Blood Phosphatase 



Kay2^ and Bodansky and Jaffe" have reported high serum phosphatase 

 (alkaline) during rickets in children, and Common^^ found the same to be 

 true during rickets in chicks. 



23 H. Steenbock, E. B. Hart, J. H. Jones, and A. Black, J. Biol. Chem. 58, 59 (1923- 

 1924). 



24 H. Steenbock, E. B. Hart, and J. H. Jones, /. Biol. Chem. 61, 775 (1924). 



25 W. J. Loeffel, R. R. Thalman, F. C. Olson, and F. A. Olson, Nebr. Agr. Expt. Sta. 

 Research Bull. 58 (1931). 



26 H. D. Kay, /. Biol. Chem. 89, 249 (1930). 



27 A. Bodansky and H. L. Jaffe, Am. J. Diseases Children 48, 1268 (1934). 



28 R. H. Common, J. Agr. Sci. 26, 492 (1936). 



