Several factors can impair B12 absorption: Reduced stomach acid production (achlorhydria or hypochlorhydria), common in older adults and those taking proton pump inhibitors or H2-receptor antagonists long-term, impairs the release of B12 from food proteins Pernicious anaemia , an autoimmune condition destroying parietal cells and reducing intrinsic factor production, completely blocks the primary absorption pathway Gastrointestinal disorders including Crohn's disease, coeliac disease, or surgical removal of stomach or ileum sections directly damage absorption sites Metformin , commonly prescribed for type 2 diabetes, may reduce B12 absorption through unclear mechanisms
974-977 Esposito, P., et al., 2003
A previous study used facial images and deep learning technology to predict anaemia in patients in the emergency department (71)
Controlled clinical trial of combined triiodothyronine and thyroxine in the treatment of hypothyroidism
L., Thgersen, H., Madsen, K., Ankersen, M., & Andersen, P