Title: The Excretion of Vitamin B1 in the Urine and Feces
Abstract: The condition of vitamin B1 excretion equilibrium is described for white rats. Rats in excretion equilibrium on levels between 15 γ and 515 γ show the following distribution of the ingested vitamin: 25 to 35% excreted via urine, 20 to 30% via feces, and the remainder unaccounted for. Animals with a previous history of low vitamin intake show a time lag before reaching excretion equilibrium. If the animal is brought to excretion equilibrium at a level between 50 to 65 γ a further increase in feeding level will show no time lag before reaching excretion equilibrium. Subcutaneous injection of 200 to 500 γ per day (rats) caused the excretion via urine of 75 to 85% of the vitamin, whereas 10-kg. dogs showed urinary excretion of only 50% of 2000 γ injected.