INTRODUCTION 

 By James E. Fuller, Department of Bacteriology 



Experts in nutrition are constantly stressing the importance of so regu- 

 lating the diet that "deficiency" ailments may be avoided. One usually 

 thinks of vitamins in this connection, and they are very important; but it 

 is now recognized that very serious consequences can result from the 

 deficiency of necessary minerals in the diets of man and animals. 



Scientific knowledge concerning the importance of minerals in food has 

 accumulated slowly. It has long l^een known tliat calcium and phosphorus 

 are required for the development of bones, that body fluids need a certain 

 concentration of common salt, that there must be iron in the hemoglobin 

 of blood if it is to carry oxygen, and that a certain amount of iodine is 

 needed to prevent the occurrence of simple goitre. These are a few ex- 

 amples of well-known mineral requirements for health. 



The knowledge of the need for some of the minerals in nutrition is 

 comparatively recent. It was demonstrated in 1925 that a diet deficient 

 in copper caused anemia in white rats, and that the anemia was relieved 

 by adding small amounts of copper salts to the diet. In 1931, some ex- 

 periments showed that white rats on a diet deficient in magnesium devel- 

 oped fatal convulsions, and a similar condition has been observed in farm 

 animals. Important discoveries were made in 1931 concerning the impor- 

 tance of manganese in the reproduction and care of the young of white 

 rats. It was reported in 1934 that insulin, used to treat diabetes, contains 

 zinc; and in 1935, that cobalt is important in the nutrition of sheep and 

 cattle. These examples are cited to illustrate the need the body has for min- 

 erals. A complete list would be quite long, and space does not permit 

 a detailed statement here of the different minerals the body needs and 

 the use it makes of them. 



The opinion is growing among pliysicians and nutrition authorities that 

 certain disabling diseases, especially arthritis and hardening of the ar- 

 teries, may be caused by lack of sufficient minerals in the diet, coupled 

 perhaps with vitamin deficiency. The studies reported in this bulletin 

 were undertaken as a co-operative project by several Departments in the 

 College in the hope that some information might be obtained concerning 

 minerals in nutrition. The investigators and their departments are indi- 

 cated in the reports which follow this preliminary review of the project. 



One of the first essentials in studying mineral deficiency in foods is a 

 knowledge of the composition of various fruits and vegetables. In section 

 I of this bulletin are presented analyses of a considerable number of 

 fruits and vegetables, as well as of some cattle feeds. The cattle feeds 

 are important because, in the case of certain minerals, if the feed has an 

 adequate mineral content the milk will be a satisfactory source of the 

 minerals. The analyses included determinations of nutrients (protein 

 and fats) and of iron, copper, manganese, and phosphorus. Accepted 

 analytical procedures were employed in making the analyses. 



Section II of this bulletin reports experiments aimed toward increasing 

 the mineral content of field crops by soil treatment. It is known that 

 soils in certain regions may lack essential minerals. In the Rocky Moun- 

 tain states and around the Great Lakes, for instance, the soil is deficient in 

 iodine and simple goitre is consequently prevalent in these regions. In 

 such circumstances, it is desirable to increase the minerals that are lack- 



