Reliability of a new technique for the determination of vitamin B12 absorption in children: single stool sample test--a double isotope technique.
The fractional vitamin B12 absorption (FAB12) was determined in 39 patients with various gastrointestinal diseases by a double-isotope technique, employing a single stool sample test (SSST), as well as a complete stool collection. The age of the patients ranged from 2.5 months to 16.2 years (mean 5.0 years). The test dose was administered orally and consisted of 0.5-4.5 micrograms of 57CoB12 (approximately 0.05 microCi), carmine powder, and 2 mg 51CrCl3 (approximately 1.25 microCi) as the inabsorbable tracer. The wholebody radiation to a 1-year-old child averaged only 20 mrad. The stool and napkin was collected and homogenized by addition of 300 ml "chromium sulfuric acid." A 300-ml sample of the homogenized stool and napkin, as well as 300 ml chromium sulfuric acid (75% v/v) containing the standards, were counted in a broad-based well counter. The FAB12 determined by SSST employing the stool with the highest content of 51Cr (which corresponded to the most carmine-colored stool) correlated closely to the FAB12 based on complete stool collection (r = 0.98, n = 39, p less than 0.001). The reproducibility of FAB12 determined by SSST was assessed from double assays in 19 patients. For a mean value of 12%, the SD was 3%, which corresponded to a coefficient of variation (CV) of 25%. The excretion of 57Co and 51Cr in the urine was examined in six patients with moderate to severe mucosal damage and was found to be low.(ABSTRACT TRUNCATED AT 250 WORDS)
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002712:Chlorides; D002857:Chromium / Q000378:metabolism; D017608:Chromium Compounds; D002860:Chromium Radioisotopes / Q000652:urine; D003037:Cobalt Radioisotopes / Q000652:urine; D005069:Evaluation Studies as Topic; D005243:Feces / Q000032:analysis*; D005767:Gastrointestinal Diseases / Q000378:metabolism; D005769:Gastrointestinal Motility; D006801:Humans; D007223:Infant; D007408:Intestinal Absorption; D014805:Vitamin B 12 / Q000378:metabolism*
D002712:Chlorides; D017608:Chromium Compounds; D002860:Chromium Radioisotopes; D003037:Cobalt Radioisotopes; D002857:Chromium; C017133:chromous chloride; D014805:Vitamin B 12