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

Abstract

Objective Acid-suppressant drugs are commonly prescribed for elderly patients, a population in which vitamin B12 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 B12 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 B12 studies between 1990 and 1997, 53 vitamin B12-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 (⩾12 months) current use of H2RA/PPI was associated with a significantly increased risk of vitamin B12 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 B12 deficiency. Conclusion These findings support an association between chronic use of H2RA/PPI by older adults and development of vitamin B12 deficiency. Additional studies are needed to confirm these findings.