Morphology, dipeptidases and disaccharidases of small intestinal mucosa in vitamin B12 and folic acid deficiency

Mucosal morphology and intestinal enzyme activities (dipeptidases and disaccharidases) were studied in 33 biopsies from 24 patients with vitamin B12 and/or folic acid deficiency. The villi were generally shorter in patients than in controls (34 subjects). The disaccharidases and L-alanyl-L-proline dipeptidase activity were depressed in about 30 % of the patients, untreated and treated. Glycyl-L-leucine and L-alanyl-L-glutamic acid dipeptidase activity was normal in untreated patients but was depressed during treatment with vitamin B12.