Abstract
A switch from an ordinary to a vegetable diet resulted in an increase both in the fecal folic acid and in the folic acid synthesized and it resulted in a further increase with an addition of cellulose. On the contrary, a switch from an ordinary to a meat diet resulted in a reduction in the fecal folic acid and the folic acid synthesized, but they were definitely enhanced when cellulose was added to the meat diet. This relationship was found to be about the same with the case of thiamine, riboflavin, niacin and pyridoxine.
