Investigators have given considerable study to the uric acid excretion of adults and to the allantoin excretion of animals, but there have been few such studies on children. In the course of three long time balance studies conducted at Michigan State College, considerable data were obtained concerning the uric acid excretion of preschool children.Rose,1 in his extensive review of the literature on purine metabolism, in 1923, clearly indicated that the uric acid excretion of man was not constant from day to day but that it varied with the proportions of protein, fat and carbohydrate in the diet. Protein, even that from puri ne\x=req-\ free sources, increased the elimination, while additional carbohydrate caused no increase unless the quantity was excessive. On the other hand, an increase in fat and also starvation produced decided decreases in the elimination.Since 1923 other investigators have confirmed these general conclusions. The majority of the studies have been conducted on subjects with disease conditions, such as gout, or on patients with epilepsy or other conditions who were being treated with starvation and ketogenic diets.There have been no studies on preschool children.The purpose of the present study was to determine the effect on the urinary uric acid excretion of young children of changes in the protein, the fat and the carbohydrate content of the diet. EXPERIMENTAL PROCEDURE During three long time balance studies conducted on preschool children, urinary uric acid determinations were made daily. In all three experiments, the children consumed a normal basal diet containing 3 Gm. of protein and 90 calories per kilogram for relatively long periods. After the basal diet, the children in the first two experiments received a diet containing 4 Gm. of protein per kilogram, while in the third experiment they had approximately a 20 per cent increase in calories. The figures for uric acid gave considerable information concerning the daily variation in excretion as well as data concerning the effects of increasing protein or calories.
