4 MISC. PUBLICATION 3 69, U. S. DEPT. OF AGRICULTUKE 



more of the inorganic nutritional elements in the food, eventually 

 resulting in bone maladies, anemia, goiter, and related diseases. The 

 second are those claimed to be the result of excesses of certain elements 

 in the soils and in the plants growing therein. Of the latter class, 

 only selenium has been extensively studied, although investigations 

 would doubtless indicate that other serious disturbances may really 

 be due to poisoning of the animal. 



The problem that confronts us is more complicated and insidious in 

 nature than that of correcting observable deficiencies in the domestic 

 animal, for although the humane and economic aspects of this part of 

 the difficulty are great, the more important aspect is man, who depends 

 upon a high quality of food for his growth, health, and reproduction. 



It is probably true that not only are a large portion of our people 

 existing on a diet deficient in the protective foods such as milk, eggs, 

 fruits, and vegetables, but also a large portion are obtaining only a 

 minimum amount of these foods. If this is true, we are then con- 

 fronted with the problem of the variation in the nutritive value of such 

 foods as the fruits and vegetables in particular. Are these fruits and 

 vegetables as highly nutritious as is possible? The calcium content of 

 cabbage, one of the most commonly used protective foods of the 

 vegetable class, may vary from 0.40 to 1.60 percent of the dry weight 

 (refer to appendix), and the average is about 0.73 percent. Com- 

 parable variations in other nutritive elements in this and other foods 

 are often reported. It is entirely probable, therefore, that the value of 

 a minimum diet of protective foods may be reduced significantly 

 below the minimum requirement through the use of inferior foods. 

 The necessity for maintaining these foods at an optimum nutritive 

 level is thus apparent. 



The problem is intensified because of the location of our large cities 

 and of our truck farms that supply these cities with food. Most of our 

 large cities are located on the well-leached Podzols and podzolic soils 

 that are acid in reaction and low in the bases. The truck farms are 

 of necessity located near the cities on the same soils, and large quan- 

 tities of truck crops and fruits are shipped to these cities from localities 

 where nutritional disorders due to mineral deficiencies in the soils 

 have been noted in both humans and animals. 



Although many factors other than the poor quality of food probably 

 are responsible for dietary difficulties, this factor is believed to be an 

 important one; and if it is important, then it certainly remains the 

 duty of the agriculturalist to supply for at least the protective portion 

 of the diet a food of the highest nutritional quality. 



SOME SOIL CHARACTERISTICS CITED IN RELATION TO THE 

 OCCURRENCE OF CERTAIN NUTRITIONAL DISEASES OF 

 MAN AND ANIMALS 



In the discussion that follows, the occurrences of certain nutritional 

 deficiency diseases are cited only as indicators of observed differences 

 in soils. No attempt has been made to discuss the diseases themselves. 



Studies of the Relation of Soils to Bone Diseases 



The occurrence of many disorders in animals, believed to be due to 

 deficiencies of elements such as calcium or phosphorus, are often sus- 

 pected to be related to deficiencies of one or more of these elements in 



