Abstract
Ariboflavinosis has been found endemically among the villager at Tsugaru District, Aomori Prefecture. Besides insufficient intake of riboflavin as well as low protein, and high carbohydrate dietary habit, which have been known as causative factors of ariboflavinosis, the well-water, passing through peat-bog widely distributed in this village, was found to exert a profound influence upon riboflavin metabolism. An acceleration of the reaction of FAD→FMN by an addition of the well-water was demonstrated in vitro as well as in vivo. It was probable that the effect of the well-water was brought about mainly by a high concentration of manganese in it. Furthermore, the well-water showed some inhibitory effect upon the intestinal synthesis of riboflavin. Macrocytic anemia, which has been found frequently among children in this village, was considered to be closely related to folic acid deficiency, from the results of folic acid load test, urinary output of formiminoglutamic acid before and after an administration of folic acid and hematologic response to the treatment with folic acid. Nuclear diameters of oral squamous epithelial cells and those of lymphocytes in peripheral blood showed a certain correlation to vitamin B_<12> level in whole blood.
