Do acid-lowering agents affect vitamin B12 status in older adults?

Objective: To examine the relationship between serum vitamin B12 levels in older adults on histamine(2) receptor antagonists (H2 blockers) or proton-pump inhibitors (PPI) over 6 years. Participants: A cross-sectional sample of 659 adults, 60 to 102 years, from long-term care facilities and community ambulatory care (C) in the Bronx. Measurements: Patient demographics, serum B12 levels, use and duration of use of H2 blockers, PPIs, antacids, multivitamin/minerals, liquid dietary supplements, oral vitamin B12 supplementation, oral or intramuscular B12 therapy, and recent lab chemistries. Results: Acid-lowering agents (ALA) were used by 54% (PPIs by 26% and H2 blockers by 28%), duration averaged 18.2 +/- 16.0 (SD) months. NH and C subjects had similar ages (P = .9971), gender distributions (P = .625), durations of ALA use (P = .1227), and rates of PPI use (P = .130); NH subjects used more H2 blockers (P < .0005) and had less low B12 status (P = .037). H2 blocker use did not influence serum B12 status (P = .1036) while PPI use was associated with diminished serum B12 levels (P < .00005). Concomitant oral B12 supplementation slowed but did not prevent the decline in B12 status during prolonged PPI use (P = .0125). Conclusions: 1312 status declines during prolonged PPI use in older adults, but not with prolonged H2 blocker use; supplementation with RDA amounts of B12 do not prevent this decline. This report reinforces that B12 deficiency is common in the elderly and suggests that it appears prudent to monitor periodically B12 status while on prolonged PPI use, to enable correction before complications ensue.