Increased Vitamin B12 Requirement Associated With Chronic Acid Suppression Therapy
Assimilation of vitamin B12 from dietary sources requires gastric acid. By decreasing acid production, the proton pump inhibitors (PPIs) and histamine2 (H2)-blockers may reduce vitamin B12 absorption.
To determine whether chronic acid suppression therapy is associated with the initiation of vitamin B12 supplementation, we conducted a retrospective case–control study using a state-wide Medicaid population.
Case patients were identified as those who initiated vitamin B12 supplementation during the study period. Four control patients were age-and gender-matched to each case. Patients (n = 109 844) with a paid claim between September 27, 1995, and September 27, 1997, were eligible for inclusion. Chronic acid suppression therapy was defined as treatment with H2-blockers or PPIs for ≥10 of the 12 months prior to the first vitamin B12 injection. Comparisons were made between the case and control groups regarding exposure to chronic acid suppression therapy.
One hundred twenty-five cases were matched to 500 controls. Twenty-three patients (18.4%) had been exposed to chronic acid suppression therapy compared with 55 (11.0%) of the control group (p = 0.025; OR 1.82; 95% CI 1.08 to 3.09).
Initiation of vitamin B12 supplementation was associated with chronic gastric acid suppression therapy.