Abstract
The effects in vivo of a biguanide (Metformin) on intestinal enzyme activities and vitamin B12 and folic acid absorption can be summarized as follows. 1. The enzyme activities of the brush border of the mucosal cell of the upper intestine were influenced. 2. The disaccharidase activities were reduced, although not to such an extent as to be expected to impair disaccharide absorption. 3. Vitamin B12 absorption was significantly reduced, as measured by Schilling test. 4. Serum folic acid levels were significantly reduced, possibly due to a decreased intestinal absorption of dietary folic acid.