Interaction Checker

Vitamin B12 interactions

Common stomach-acid reducers and metformin lower B12 absorption over time.

Vitamin B12 has 16 documented interactions across the FDA labels and fact sheets we index: 0 major, 10 moderate, 6 minor, and 0 where a label reports no significant interaction. Each entry below quotes the sentence behind it. This vitamin and mineral page is a starting point, not a verdict for your situation.

Moderate interactions (10)

  • Dexlansoprazoleproton pump inhibitorModerate

    This diagnosis should be considered if clinical symptoms consistent with cyanocobalamin deficiency are observed in patients treated with DEXILANT. (Dexlansoprazole label, Warnings and precautions)

  • Empagliflozin and metforminSGLT2 inhibitorModerate

    Vitamin B 12 Deficiency In metformin HCl clinical trials of 29-week duration, a decrease to subnormal levels of previously normal serum vitamin B 12 levels was observed in approximately 7% of metformin-treated patients. (Empagliflozin and metformin label, Warnings and precautions)

  • Esomeprazoleproton pump inhibitorModerate

    This diagnosis should be considered if clinical symptoms consistent with cyanocobalamin deficiency are observed. (Esomeprazole label, Warnings and precautions)

  • Glyburide and metforminsulfonylureaModerate

    Vitamin B12 Deficiency In clinical studies of 29-week duration with metformin HCl tablets, a decrease to subnormal levels of previously normal serum vitamin B 12 levels, was observed in approximately 7% of patients. (Glyburide and metformin label, Warnings and precautions)

  • Lansoprazoleproton pump inhibitorModerate

    This diagnosis should be considered if clinical symptoms consistent with cyanocobalamin deficiency are observed in patients treated with PREVACID or PREVACID SoluTab. (Lansoprazole label, Warnings and precautions)

  • MetforminbiguanideModerate

    Monitor hematological parameters annually and vitamin B 12 at 2 to 3 year intervals and manage any abnormalities. (Metformin label, Warnings and precautions)

  • Omeprazoleproton pump inhibitorModerate

    This diagnosis should be considered if clinical symptoms consistent with cyanocobalamin deficiency are observed in patients treated with PRILOSEC. (Omeprazole label, Warnings and precautions)

  • Pioglitazone and metforminthiazolidinedioneModerate

    Monitor hematologic parameters annually and vitamin B 12 at 2 to 3 year intervals and manage any abnormalities. (Pioglitazone and metformin label, Warnings and precautions)

  • Rabeprazoleproton pump inhibitorModerate

    This diagnosis should be considered if clinical symptoms consistent with cyanocobalamin deficiency are observed in patients treated with ACIPHEX. (Rabeprazole label, Warnings and precautions)

  • Sitagliptin and metforminDPP-4 inhibitorModerate

    Vitamin B 12 Deficiency In controlled clinical trials of metformin of 29 weeks duration, a decrease to subnormal levels of previously normal serum vitamin B 12 levels was observed in approximately 7% of patients. (Sitagliptin and metformin label, Warnings and precautions)

Minor mentions (6)

  • CimetidineH2 blockerMinor

    Long-term acid-reducing therapy interferes with B12 absorption from food and can lead to deficiency. (NIH Office of Dietary Supplements, Vitamin B12)

  • FamotidineH2 blockerMinor

    Long-term acid-reducing therapy interferes with B12 absorption from food and can lead to deficiency. (NIH Office of Dietary Supplements, Vitamin B12)

  • HydroxyureaantimetaboliteMinor

    The morphologic change resembles pernicious anemia, but is not related to vitamin B12 or folic acid deficiency. (Hydroxyurea label, Warnings and precautions)

  • NeomycinaminoglycosideMinor

    Oral neomycin inhibits the gastrointestinal absorption of penicillin V, oral vitamin B-12, methotrexate and 5-fluorouracil. (Neomycin label, Drug interactions)

  • NizatidineH2 blockerMinor

    Long-term acid-reducing therapy interferes with B12 absorption from food and can lead to deficiency. (NIH Office of Dietary Supplements, Vitamin B12)

  • Pantoprazoleproton pump inhibitorMinor

    Long-term acid-reducing therapy interferes with B12 absorption from food and can lead to deficiency. (NIH Office of Dietary Supplements, Vitamin B12)

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Not medical advice. Severity reflects the label's wording, not your circumstances. A "major" flag can be routine under supervision and a "minor" one can matter at high doses. Ask a pharmacist.