ON THE METABOLITES OF ASCORBIC ACID, ESPECIALLY OXALIC ACID, ELIMINATED IN URINE, FOLLOWING THE ADMINISTRATION OF LARGE AMOUNTS OF ASCORBIC ACID

Abstract

Large amounts of ascorbic acid are recently used in curing pigment anomalies. Investigation was therefore carried out in animals and man on the fate of the vitamin administered in large amounts, especially on the excretion of oxalic acid and the following findings were obtained. After administration of the large amounts of ascorbic acid, it was eliminated in urine mostly in the form of dehydroascorbic acid in the majority of cases (about 80%). When ascorbic acid was administered orally or intramuscularly in a dose of 3 g per day, there was no marked increase in the urinary oxalic acid. Oral administration of 9 g of the vitamin resulted in an marked increase of the urinary oxalic acid (from 20 to 30 mg). With a rise in the dose of ascorbic acid, urinary diketogulonic acid was increased. It seems to indicate that the large dose of ascorbic acid promotes the degradation of dehydroascorbic acid Into digekogulonic acid, but further oxidation to oxalic acid does not occur markedly. The amounts of oxalic acid-c14 detected in the urine of animals and man following the administration of AsA-C14 accounted for 1.0 to 1.5% and 0.16% of the C14 given in animals nd man respectively. Investigation on the effect of an intravenous an injection of a daily dose of 0.5 mg of ascorbic acid carried out for 17 consecutive days on the formation of calculi with a lead ball inserted in the urinary bladder as a nucleus showed that the calculi formed around the nuclei in experimental animals was 7 times as heavy as those formed in the control animals. The amount of oxalic acid contained in the calculi was 0.73 mg as contrasted to 0.33 mg in the calculi of the control animals.