To the Editor Mr Lam and colleagues1 reported that previous and current gastric acid–inhibiting medication use for 2 or more years (proton pump inhibitors [PPIs] and histamine 2 receptor antagonists [H2RAs]) was associated with a greater risk of vitamin B12 deficiency; this association became stronger with increasing daily consumption of PPIs or H2RAs. The study is, to date, the largest study suggesting a relationship between PPIs or H2RAs and vitamin B12 deficiency. Lam et al1 confirmed and extended the results from 2 earlier, small studies2,3 that also suggested PPI use was associated with diminished vitamin B12 status.
Dharmarajan TS, Norkus EP. Gastric Acid–Inhibiting Medications and Vitamin B12 Deficiency. JAMA. 2014;311(14):1444-1445. doi:10.1001/jama.2014.2095