Diet in Rickets Production 



21 



inite data on which to base this assumption. Furthermore, 

 Schabad 2 has shown that in active rickets the distribution of cal- 

 cium and phosphorus between urine and feces is such as we now 

 know will occur with insufficient acidity of intestinal contents. 

 We believe that in some of our rat experiments we have supplied 

 evidence pointing in the direction of Schloss's hypothesis. On 

 a diet consisting of flour, casein, calcium lactate, sodium chloride, 

 and a trace of ferric citrate, rats will regularly develop a rather 

 marked rickets as shown by X-ray and microscopic sections of 

 ribs. This diet, like practically all diets used in rickets produc- 

 tion, contains a large excess of base-ion over acid-ion, the lactic 

 acid of the calcium lactate being a weak acid, while calcium is a 

 strong base. When we substitute, in this diet, calcium chloride 

 for calcium lactate in equivalent quantities, we markedly increase 

 the acidity. Such a diet, when fed to rats, resulted in bone 

 growth so nearly normal that it could not be called more than 

 minimal rickets, while the control rats getting calcium lactate 

 developed a very marked rickets. In another set of experiments, 

 we made the rickets producing diet mentioned above more acid 

 by addition of 2 per cent, of ammonium chloride. The rats 

 receiving ammonium chloride developed no rickets, while those 

 on the control diet showed, as always, perfectly definite rickets. 

 We think, therefore, that without modifying any of the factors 

 discussed heretofore, we can change a rachitic into a non-rachitic 

 diet. 



The reverse of the above experiments was obtained on certain 

 diets made up of flour and egg albumen together with a suitable 

 salt mixture. The control rats were given an egg albumen-flour 

 diet to which enough potassium phosphate had been added to 

 prevent development of rickets. To this diet was added 2 per 

 cent, of sodium carbonate making the diet extremely alkaline. 

 On the latter diet rats developed a very marked rickets. Thus 

 we have changed a non-rachitic diet into a rachitic diet without 

 changing the calcium or phosphorus intake in the food or any 

 of the other known factors which affect rickets. The growth 

 curves of these rats were all approximately the same, thus ruling 

 out the question of total food intake. 



If we consider that the digestive tract is capable of a good deal 



2 Schabad, Ztschr, f. Jclin. Med., 1909, lxviii, 94. 



