Proton-pump inhibitor therapy and vitamin B₁₂ status in an inpatient hospital setting

The risk for impaired vitamin B₁₂ status increases with age, as does the use of proton pump inhibitors (PPI). Long-term use of PPIs is associated with several nutritional deficiencies including B₁₂. Currently, there are no recommendations for B₁₂ screening among patients taking PPIs. Data were abstracted on B₁₂ concentrations, B₁₂-containing supplement use, medications, and select hematological values from a retrospective chart review of 658 adults, 391 with serum B₁₂ concentrations, admitted to 6 different medical units at 2 regional hospitals in Southwestern Ontario between 2010 and 2012. We found no difference between PPI users and nonusers and serum B₁₂ concentrations (404 ± 224 vs 369 ± 213 pmol/L; P = 0.0690). This may be due to use of B₁₂ containing multivitamins in 41% of PPI users. Regression modelling found that aging increases the odds of having an impaired B₁₂ status (<220 pmol/L) by 1.4 times and those using B₁₂ supplements are almost 4 times more likely to have an impaired status. Mean corpuscular volume was not related to B₁₂ status. In this population, older PPI users are more likely to be using multivitamins, which may delay nutritional deficiencies. However, the lower B₁₂ concentrations of PPI users taking only B₁₂ supplements is a concern and requires further research. Finally, physicians need to be aware that mean corpuscular volume is no longer recommended as an effective biomarker for B₁₂ screening and updated screening protocols need to be used to reduce the possibility of adverse neurological effects from impaired B₁₂ status.