For several years we have been studying the vitamin B1 (thiamine) requirements of infants and children. In order to determine the factors which affect the amount of thiamine required, we have analyzed its excretion in urine and feces under various conditions and have also studied the effects of administering supplements of thiamine hydrochloride.
We now wish to report a new phase of our work. For the first time we have been able to measure the amount of thiamine circulating in the body. In this investigation we have determined the amounts of cocarboxylase in the blood of infants and children who exhibited pathologic conditions of varying severity. We have been specifically interested in cocarboxylase, since it is the active, phosphorylated form of thiamine.
Goodhart and Sinclair1 have recently published two papers on the amount of cocarboxylase in the blood of adult subjects. They found that the range for 26