Experimental rickets

Abstract

In a large number of experiments on feeding albino rats in which white wheat flour was used as the main part of the ration, bone abnormalities were absent or transitory. Since Sherman showed that rickets could be inhibited by simply adding phosphate to the diet we concluded that the normal condition of the bones of our rats was due to the phosphoric acid content of the casein used in the diet. After substituting casein by lactalbumin or edestin, bone abnormalities appeared in one hundred per cent. of our rats. If casein was fed to the extent of 6 per cent. of the ration bone abnormalities were reduced and apparently the disturbance was transitory, since the bones became hard and cast dense shadows with the x-rays without changing the diet, yet some of the deformities were preserved. With a basic ration of white flour containing 6 per cent. sea salt, the addition of edestin or lactalbumin to improve the protein did not in any way decrease the abnormalities. The edestin carries vitamine B and if wheat germ extract is added to the lactalbumin in order to furnish vitamine B, the abnormalities still persist. The addition of spinach up to 5 per cent. of the ration did not decrease the abnormalities, whereas 0.2 per cent. furnished sufficient vitamine A to keep the animal alive for 3 or more months. The addition of 0.5 gram of butter fat per day did not lessen the abnormalities. In order to determine the growth of the bones x-ray plates were made by photographing a large number of animals on the same plate and comparing the density of the shadows of the bones. In addition, determinations of calcium intake and output and calculations of the calcium retention were made.