Abstract
When male albino rats were fed with a vitamin B_1-deficient diet designed by Gubler, ^<1)> the contents of vitamin B_6 and vitamin B_<12> in the blood after 3 weeks feeding decreased to 1/2 and 1/3 those of the pair-fed animals, respectively. Daily oral administration of insufficient amounts of vitamin B_1 to the vitamin B_1-deficient animals maintained their lives for 8 days or so. Daily supplement of vitamin B_6 and vitamin B_<12> to the B_1-insufficient level could elongate the survival of the vitamin B_1-deficient rate more than 20 days. These facts suggest that there would exist some interrelationships among vitamin B_1,B_6 and B_<12> in their blood contents and physiological functions in the animal.
