Drug‐Induced Malabsorption of Vitamin B₁₂: V. Intestinal pH and Absorption of Vitamin B₁₂during Treatment with Para‐Aminosalicylic Acid

Abstract

The pH in the contents of the ileum was measured radiotelemetrically in 11 patients taking PAS for pulmonary tuberculosis and having subnormal Schilling test values. In 8 cases, the pH was above 6. At that level the intrinsic factor has been found to enhance the uptake of B12 in the ileal mucosa. The present finding is in agreement with earlier studies, indicating that PAS does not interfere with the intrinsic factor by any means, but causes B12 malabsorption by another mechanism.

The Relevance of Vitamin and Iron Deficiency in Patients with Inflammatory Bowel Diseases in Patients of the Swiss IBD Cohort

“…10 Because ileal location of CD or ileocecal resections may lead to vitamin B12 malabsorption, it is anticipated that patients with CD are at greater risk for deficiency. [11][12][13][14] Other less frequent causes of vitamin B12 deficiency may be fistulas, small intestinal bacterial overgrowth (SIBO), reduced alimentary intake, increased physiologic requirements, protein losing enteropathy, and hepatic dysfunction. 15,16 Folate deficiency is common in IBD patients and often linked to sulfasalazine and/or methotrexate (MTX) therapy.…”