The close relation between thiamine and carbohydrate metabolism is well established. In uncomplicated diabetes mellitus the evidence for the value of therapeutic doses of vitamin B complex is confusing. Trasoff and Bordin1 reviewed the literature and reported their experience with administering thiamine hydrochloride to 15 diabetic patients. They observed no significant improvement in the patients studied which they could attribute to the thiamine therapy. They pointed out that "in a clinical investigation of this nature where the laboratory reports occupy such an important place and where there is a likelihood of variations due to many factors, one must be careful in accepting a blood-sugar lowering 10-20 per cent or thereabouts as positive proof of the beneficent effect of Vitamin B1. Over-enthusiasm may lead to erroneous conclusions." Smith and Mason2 reported no change in the insulin requirement of diabetic subjects following thiamine deprivation and therapy.
In former publications
JACKSON RL, BARTH I. EFFECT OF ADDING VITAMIN B COMPLEX TO THE DIETS OF STABILIZED DIABETIC CHILDREN. Am J Dis Child. 1941;62(3):516–520. doi:10.1001/archpedi.1941.02000150040006