NutriStack
Esomeprazole and Vitamin B12, a caution.
Long-term esomeprazole therapy reduces vitamin B12 absorption. PPIs suppress the gastric acid and pepsin needed to liberate dietary B12 from food proteins, and chronic use of two or more years is associated with a roughly 65% higher risk of B12 deficiency. Older adults, vegetarians, and people on PPI plus metformin are at greatest risk.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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What the row says.
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At a glance
- Substances
- Esomeprazole and Vitamin B12
- Pair type
- Caution
- Evidence (highest tier)
- Strong
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Strong evidence
Caution
What is happening. Long-term esomeprazole therapy reduces vitamin B12 absorption. PPIs suppress the gastric acid and pepsin needed to liberate dietary B12 from food proteins, and chronic use of two or more years is associated with a roughly 65% higher risk of B12 deficiency. Older adults, vegetarians, and people on PPI plus metformin are at greatest risk.
Mechanism. Esomeprazole irreversibly inhibits the gastric H+/K+-ATPase, raising intragastric pH and impairing acid-pepsin-dependent cleavage of cobalamin from dietary protein. Free cobalamin must be liberated before it can bind intrinsic factor for ileal absorption.
Recommendation. If you take esomeprazole for more than two years, ask your prescriber to check serum B12 (and ideally methylmalonic acid) annually. Consider a daily B12 supplement, especially the methylcobalamin form, which does not require gastric acid for absorption.
Sources (3)
- Lam JR, Schneider JL, Zhao W, Corley DA. Proton pump inhibitor and histamine 2 receptor antagonist use and vitamin B12 deficiency. JAMA. 2013;310(22):2435-42. PMID 24327038
- Choudhury A, Jena A, Jearth V, et al. Vitamin B12 deficiency and use of proton pump inhibitors: a systematic review and meta-analysis. Expert Rev Gastroenterol Hepatol. 2023;17(5):479-87. PMID 37060552
- Miller JW. Proton Pump Inhibitors, H2-Receptor Antagonists, Metformin, and Vitamin B-12 Deficiency: Clinical Implications. Adv Nutr. 2018;9(4):511S-518S. PMID 30032223
Stack Score
How this pair moves the number.
Effect on the composite score
If both Esomeprazole and Vitamin B12 are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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