The role of the exocrine pancreas in early-onset vitamin B12 malabsorption in gluten-challenged celiac children.
The fractional absorption of vitamin B12 (FAB12) was measured by a double-isotope technique specially adapted for children. In six celiac children on a strict gluten-free diet and with a normal small intestinal biopsy, the FAB12 performed in the fasting patient averaged 30% (23-40%). After gluten challenge for a mean of 2 months (range 1-4), when mucosal damage was demonstrated by biopsy, the average fasting FAB12 in these patients decreased to 10% (0-17%) (p less than 0.05). However, when the FAB12 test was repeated by means of stimulation by a B12-free meal 1-3 weeks later, while the patients were still on a diet containing gluten, a significant increase was observed (mean 21%, range 14-27%) (p less than 0.05). In four of the six patients the B12 absorption was further evaluated by repeating the FAB12 test by means of intravenous cholecystokinin (CCK) stimulation (n = 3) or by administration of exocrine pancreas enzyme supplementation (EPES) (n = 2) or cobinamide (n = 1). These tests all showed FAB12 values within the range of the meal-stimulated FAB12. Moreover, in eight gluten-free celiac children with normal biopsies, no difference was found between fasting and meal-stimulated FAB12 values. Therefore, it is likely that the early-onset B12 malabsorption observed in the gluten-challenged celiac child with upper-small-intestinal mucosal damage is in part due to an insufficient stimulation of the exocrine pancreas when using the standard fasting B12 absorption test.(ABSTRACT TRUNCATED AT 250 WORDS)
Pediatric Department, Gentofte Hospital, University of Copenhagen, Denmark.
K
K
Hjelt
D000293:Adolescent; D002446:Celiac Disease / Q000150:complications* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005983:Glutens / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D007408:Intestinal Absorption / Q000502:physiology*; D010179:Pancreas / Q000503:physiopathology*; D014806:Vitamin B 12 Deficiency / Q000209:etiology / Q000503:physiopathology*
D005983:Glutens