Application of Whole Body Counting to the Measurement of Vitamin B12Absorption with Reference to Achlorhydria

Abstract

Three hundred vitamin B₁₂ (B₁₂) absorption tests were carried out by whole body counting: sequential scanning may detect errors due to un-absorbed and unexcreted radioactivity. There was a poor correlation between two successive absorption tests in the same patient in the fasting state. The correlation improved when B₁₂-free meals were used, particularly in controls and achlorhydric patients without pernicious anaemia (PA). Single tests in the fasting state could not always distinguish between patients with and with-without PA. No constant relationship between intrinsic factor (IF) production following histamine or pentagastrin stimulation and B₁₂ absorption could be found in achlorhydric patients without small intestinal disease.