VI. EFFECTS OF DEFICIENCY 223 



The older literature contains many references to assays reported in terms 

 of vitamin D units no longer in use. The values of the various systems are 

 compared in Table IX. 



VI. Effects of Deficiency 



A. IN ANIMALS 



JAMES H. JONES 



The over-all effect of a deficiency of vitamin D in the higher animals is 

 known as rickets. According to Park,^ Jost and Koch have stated that 

 rickets is a common disturbance among puppies, pigs, lambs, and kids but 

 occurs less frequently among colts, calves, and rabbits. However, from at 

 least four different Agricultural Experiment Stations in this country have 

 come reports of either spontaneous or experimental rickets in calves,^"^ and 

 poultry should also be added to the above list. Rodents, such as the rat, 

 are not so susceptible to rickets as the higher mammals and poultry. Rickets 

 in this type of animal can be produced only if the diet is abnormal with 

 respect to calcium or phosphorus as well as deficient in vitamin D. 



McCollum et al.,^ Sherman and Pappenheimer,^ and Steenbock and 

 Black^ have developed diets which will produce rickets in rats. All these 

 diets are composed principally of cereals and are high in calcium and 

 moderately low in phosphorus. Part of the phosphorus in these diets is in 

 the form of phytic acid, and the high calcium increases the unavailability 

 of this form of phosphorus.^ The above diets are all of the low phosphorus 

 -high calcium type, but if the phosphorus is sufficiently low, rickets in rats 

 can be produced without increasing the calcium to unusually high levels.'" 



The low phosphorus type of rickets in rats simulates rickets in humans, 



> E. A. Park, Phijsiol. Revs. 3, 106 (192.3). 



2 S. I. Bechdel, K. G. Laridsburg, and O. J. Hill, Penna. Afjr. Expl. Sta. Bull 291 

 (1933). 



3 I. W. Rupel, G. Bohstedt, and E. B. Hart, Wis. A(/r. Expt. Sta. Research Bull. 

 115 (1933). 



* H. E. Bechtel, E. T. Hallman, C. F. Huffman, and C. W. Duncan, Mich. Agr. 



Expt. Sta. Tech. Bull. 150 (1936). 

 5 J. W. Hibbs, W. E. Krauss, C. F. Monroe, and W. D. Poundon, Bimonthly Bull. 



Ohio Expt. Sta. 30, No. 232 (1945). 

 8 E. V. McCollum, N. Simmonds, P. G. Shipley, and E. A. Park, Bull. JohnsHopkins 



Hosp. 33, 31 (1922). 

 ^H. C. Sherman and A. M. Pajjpeidieimer, J. Expll. Med. 34, 189 (1921). 

 «H. Steenbock and A. Black, J. Biol. Chem. 64, 263 (1925). 

 I 9 H. M. Bruce and R. K. Callow, Biochem. J. 28, 517 (1934). 

 'oj. H. Jones, J. Nutrition 28, 7 (1944). 



