That citrus fruits are a base-forming article of diet has long been considered as established, and on this fact many dietary uses have been recommended. Sherman and Sinclair 1 were the first to attack this problem, and it was further worked on by Blatherwick and his co-workers.2 However, Blatherwick indicated in one of his recent articles that there is a possibility that the ingestion of large amounts of acid causes an excretion of an increased amount of acid in the urine. In order to study the effect of ingestion of large amounts of organic fruit acid, citric acid was fed under varying conditions to hogs, as they seemed the best suited animal for the investigation. As it was difficult to obtain sufficient amounts of citric acid through fruits, citric acid was fed direct, mixed with the weighed ration, and the urine was collected from a metabolism cage, and analyzed.
WOODS EB. CITRIC ACID METABOLISM AS INDICATED BY URINARY EXAMINATION. JAMA. 1927;88(3):169. doi:10.1001/jama.1927.02680290031009