Proton Pump Inhibitor Use and the Ability to Replete Iron Stores

Oral iron absorption occurs in the duodenum and requires increased gastric acidity to allow iron to remain in the more soluble, ferrous form. Many patients with iron deficiency anemia who require oral iron repletion are on proton pump inhibitors (PPIs) for management of various conditions that require acid suppression for treatment. In vitro studies suggest that inhibition of gastric acid secretion decreases the bioavailability of iron.

In patients with established iron deficiency anemia who are on PPIs, there is a paucity of data regarding the efficacy of iron replacement with concomitant PPI use. Sharma et al. published a case report on 2 patients who were iron deficient and on PPI therapy (Sharma et. al. Southern Medical Journal 2004). Their findings showed that discontinuation of the PPI resulted in improvement of iron deficiency anemia on the same dose of oral iron replacement. Additionally, Hutchinson et al. demonstrated that in individuals with hereditary hemachromatosis, those on PPIs had a significant reduction in phlebotomy requirements needed to keep serum ferritin ∼50μg (Hutchinson et. al. Gut 2007).

We conducted a retrospective study to assess whether a difference exists in terms of iron repletion between patients on a PPI versus those not on a PPI.

Patients were selected from the medical primary care clinic from charts dating January 2000 until January 2009. Included patients were adults older than 18 years of age, a diagnosis of iron deficiency based on ferritin < 30 with at least one follow up ferritin value, and recipients of oral iron replacement. Excluded patients were those with chronic active bleeding and anemia of chronic disease. Indices examined include iron (Fe), total iron binding capacity (TIBC), ferritin, transferrin saturation, hemoglobin (Hb), hematocrit (Hct), and mean corpuscular volume (MCV). The primary endpoint of interest is repletion of iron stores defined by ferritin > 30. Those who were able to replete their iron stores are termed “responders” and those who were not are termed “nonresponders”.

Forty-five patients have been identified who have met the above criteria. Of these patients, 14 were on a PPI and 31 were not on a PPI. Of the patients not on a PPI, 38.7% responded to oral iron. Of the patients on a PPI, 50.0% responded to oral iron. The average initial and final values of indices of interest were compared between the groups (Table 1).

Our data suggests that patients both on and off PPIs show the ability to replete their iron stores. Furthermore, it appears that a slightly greater percentage of patients on a PPI compared with those not on a PPI are able to replete their iron stores, though the numbers remain small. Most importantly, these findings challenge the commonly held belief that PPI use impairs oral iron absorption. A prospective study is warranted to further confirm these observational data.

No relevant conflicts of interest to declare.