Drug interactions
Lansoprazole + Vitamin B12
Severity: Minor
Lansoprazole and Vitamin B12: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Long-term proton pump inhibitor use lowers gastric acid, which reduces release of vitamin B12 from dietary protein. Prolonged therapy may contribute to reduced B12 status, particularly in older patients or those with marginal intake. Crystalline B12 supplements are less affected than food-bound B12.
What this interaction means in plain words
Lansoprazole and Vitamin B12 have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Lansoprazole belongs to Gastrointestinal Tract; Vitamin B12 belongs to Gastrointestinal Tract.
Why it happens
Reduced gastric acid and pepsin activity impairs liberation of protein-bound vitamin B12 for absorption.
What to do
Check serum B12 (with methylmalonic acid if borderline) in patients on long-term lansoprazole, especially if elderly or symptomatic. Supplement orally or parenterally if deficiency is found.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Vitamin B12
- Chloramphenicol + Vitamin B12 Moderate
- Dichlorphenamide + Vitamin B12 Moderate
- Metformin + Vitamin B12 Moderate
- Neomycin po + Vitamin B12 Moderate
- Aspirin / citric acid / sodium bicarbonate + Vitamin B12 Minor
- Aspirin + Vitamin B12 Minor
Other interactions of Lansoprazole
- Lansoprazole + Mavacamten Contraindicated
- Lansoprazole + Rilpivirine Contraindicated
- Acalabrutinib + Lansoprazole Major
- Atazanavir + Lansoprazole Major
- Dacomitinib + Lansoprazole Major
- Dasatinib + Lansoprazole Major
Frequently asked questions
Can I take Lansoprazole with Vitamin B12?
MediHelp rates the interaction as minor. Lansoprazole and Vitamin B12 have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Long-term proton pump inhibitor use lowers gastric acid, which reduces release of vitamin B12 from dietary protein. Prolonged therapy may contribute to reduced B12 status, particularly in older patients or those with marginal intake. Crystalline B12 supplements are less affected than food-bound B12.
How serious is the interaction between Lansoprazole and Vitamin B12?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check serum B12 (with methylmalonic acid if borderline) in patients on long-term lansoprazole, especially if elderly or symptomatic. Supplement orally or parenterally if deficiency is found.
What other medicines interact with Vitamin B12?
MediHelp also lists interactions of Vitamin B12 with, for example, Chloramphenicol, Dichlorphenamide, Metformin. The full list is on the Vitamin B12 page.
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