PATHOLOGY OF METABOLISM IN INFANCY 805 



other words, less building up of body protoplasm. Especially noticeable 

 are the effects of carbohydrate deprivation on very young infants. Under 

 normal conditions, for example, in an infant fed at the breast, carbo- 

 hydrate furnishes a very large part of the energy requirement and when 

 this element of the food is lacking fat and protein must be metabolized 

 instead. The infant organism does not seem to be able to adapt itself to 

 the use of such a fuel. Infants fed on insufficient carbohydrate do not 

 thrive and may develop a moderate degree of acidosis due to the acetone 

 bodies. If such a diet is continued any length of time, collapse and death 

 occur. No extensive metabolic studies have been made on infants fed in 

 this manner. 



Disturbances Due to a Deficiency in the Mineral 

 Salts oi the Diet 



Human milk seems to contain sufficient mineral salts for the demands 

 of the normal infant, with the possible exception of iron. There is no 

 evidence that a breast fed infant's nutrition may be benefited by the ad- 

 dition of extra mineral salts to the dietary. 



Cow's milk contains three times the amount of mineral matter as 

 does human milk, but the proportions in which the different mineral con- 

 stituents occur are different. There is, in cow's milk, as compared with 

 human milk a relative excess of calcium and phosphoric acid, a moderate 

 excess of sodium salts and a deficiency in potassium salts. When cow's 

 milk is diluted to the extent customary in preparing it for infant feed- 

 ing, the amount of mineral salts present is still sufficient for the normal 

 infant, as is shown by the very satisfactory results following the feeding 

 such milk dilutions. On account of the relatively small amount of potas- 

 sium salts present in cow's milk, it has been suggested that an addition of 

 potassium salts to cow's milk dilutions might be indicated. Friedenthal 

 was probably the first to attempt this form of modification of the mineral 

 content of the milk. Numerous other investigators have since tried out 

 the effects of such additions of potassium salts but the evidence is by 

 no means conclusive that ^uch a procedure is of benefit in the nutrition 

 of infants. It is not surprising that this should be the case as even those 

 infants who are fed on dilute cow's milk excrete a certain amount of potas- 

 sium salts in the urine, this being fair evidence that sufficient potassium 

 salts have been absorbed to supply the demands of the body and that what 

 is eliminated is an unrequired excess. 



The administration to infants of a diet in which the mineral salts have 

 been reduced to a minimum (as in the treatment of eczema) results in a 

 rapid loss of weight If such a diet is continued for a long period collapse 

 may occur. 



