Effect of long-term acid suppression therapy with proton pump inhibitors or H2 receptor blockers on serum vitamin B12 levels in elderly population.

Prolonged acid suppression therapy with PPIs or H2 blockers may result in serum vitamin B12 deficiency. However, there was no class (PPIs vs. H2 receptor blockers)- or drug (pantoprazole vs. omeprazole vs. ranitidine)-based differences found in the vitamin B12 deficiency caused.