The ‘Thiamin-Sparing’ Effect of Ascorbic Acid

Abstract

The thiamin status of 16 female geriatric patients was investigated by means of the thiamin pyrophosphate stimulating effect (TPP effect) on the thiamin pyrophosphate-dependent transketolase enzyme activity. These patients had values for the TPP effect which were greater than the suggested normal limit of 10%, and these results indicated that they had some degree of thiamin deficiency. The TPP effect was, however, significantly reduced and excretory levels of thiamin were significantly increased in these patients by oral supplementation with ascorbic acid for 1 week, the dose being 1 g daily. Oral supplementation with a loading dose of ascorbic acid also resulted in an increased urinary level of thiamin in a group of healthy subjects.