A case-control study on adverse effects:: H2 blocker or proton pump inhibitor use and risk of vitamin B12 deficiency in older adults

Objective: Acid-suppressant drugs are commonly prescribed for elderly patients, a population in which vitamin B-12 deficiency is a common disorder. The purpose of this study was to examine the possible association between use of prescription histamine H-2 receptor antagonists (H2RA) or proton pump inhibitors (PPI) and vitamin B-12 deficiency in older adults. Study Design and Setting: This was a case-control study in a University-based geriatric primary care setting. Among patients aged 65 years or older with documented serum vitamin B-12 studies between 1990 and 1997, 53 vitamin B-12-deficient cases were compared with 212 controls for past or current use of prescription H2RA/PPI according to information in subjects' medical records. Results: Controlling for age, gender, multivitamin use, and Helicobacter pylori infection, chronic (greater than or equal to 12 months) current use of H2RA/PPI was associated with a significantly increased risk of vitamin B-12 deficiency (OR 4.45; 95% CI 1.47-13.34). No association was found between past or short-term current use of H2RA/PPI and vitamin B-12 deficiency. Conclusion: These findings support an association between chronic use of H2RA/PPI by older adults and development of vitamin B-12 deficiency. Additional studies are needed to confirm these findings. (C) 2004 Elsevier Inc. All rights reserved.