Abstract
The metabolism of thiamine in vivo was investigated after administration of TPD-^<35>S (inner) and thiamine-^<35>S to rabbits. In the case of intravenous injection of TPD-^<35>S urinary ^<35>S excretion was lower than that of thiamine-^<35>S. However, in the case of oral administration, ^<35>S derived from TPD-^<35>S was excreted more than that from thiamine-^<35>S. It was confirmed that in both cases only free thiamine was detected in urine by actigraph.