Can daily use of a proton‑pump inhibitor (PPI) cause low ferritin in a 22‑year‑old athletic female with heartburn/reflux?

Yes, daily PPI use can cause low ferritin in a 22-year-old athletic female with heartburn/reflux.

Proton pump inhibitors are strongly associated with iron deficiency, particularly with prolonged use (≥2 years) and higher doses, which directly impairs iron absorption through both gastric acid suppression and hepcidin upregulation.

Mechanism and Evidence Strength

PPIs cause iron deficiency through two distinct pathways:

• Gastric acid suppression: Reduces conversion of ferric iron (Fe³⁺) to absorbable ferrous iron (Fe²⁺) in the duodenum
• Direct hepcidin upregulation: PPIs increase hepcidin expression via the aryl hydrocarbon receptor pathway, which downregulates ferroportin (the iron export protein), blocking iron absorption even independent of pH changes 1

The evidence is robust. A large nested case-control study from Kaiser Permanente (77,046 cases) found that ≥2 years of PPI use was strongly associated with iron deficiency (adjusted OR: 2.49; 95% CI: 2.35-2.64), with dose-dependent effects—higher doses (>1.5 pills/day) showed even stronger associations (adjusted OR up to 4.27 for >10 years of high-dose use) 2. A 2023 meta-analysis confirmed this relationship (RR 2.56; 95% CI 1.43-4.61) 3.

Clinical Context for This Patient

This 22-year-old athletic female faces compounded risk:

• Athletic females have baseline higher iron requirements due to menstrual losses and increased red blood cell turnover from training
• Young age typically protects against PPI complications, but iron deficiency is an exception that occurs across all age groups
• The association strengthens after ≥1 year of continuous use and increases with duration 2

Guideline-Based Approach

Recent AGA guidelines (2022) emphasize that most patients with uncomplicated GERD (heartburn/reflux) should be considered for PPI de-prescribing 4. For a young patient with simple reflux symptoms:

1. Verify ongoing indication: Heartburn/reflux in a 22-year-old without erosive esophagitis (LA grade C/D), Barrett's esophagus, or peptic stricture is NOT a definitive indication for chronic PPI use 4

2. Consider de-prescribing trial: Most GERD patients have nonerosive disease and can manage with lifestyle modifications or on-demand therapy 4

3. If PPI continuation is necessary: Step down to lowest effective dose (once daily standard dose maximum), as higher doses show stronger associations with iron deficiency 5, 2

Practical Management

For this specific patient:

• Check serum ferritin, complete blood count, and consider iron studies if ferritin is low
• If iron deficiency is confirmed and no other bleeding source exists, PPI-induced malabsorption is the likely culprit
• Attempt PPI discontinuation with lifestyle modifications (elevate head of bed, avoid late meals, weight loss if applicable)
• If symptoms recur, use lowest effective dose or switch to on-demand therapy
• The risk decreases after medication discontinuation (P-trend <0.001) 2

Important Caveats

• Do NOT discontinue if she has documented severe erosive esophagitis, Barrett's esophagus, or peptic stricture 4
• H2-receptor antagonists also increase iron deficiency risk (OR: 1.58), though less than PPIs 2
• Iron supplementation while continuing PPI may be less effective due to ongoing malabsorption 1
• The 2021 guideline on micronutrient effects notes that duration and dosage are key effect modifiers—even patients taking multivitamins with 100% DV of nutrients showed inverse correlation between PPI duration and nutrient status 5

Bottom line: In a young athletic female without complicated GERD, the PPI should be discontinued or minimized to prevent ongoing iron malabsorption, as this population already faces elevated iron requirements.