Vitamin B12 interactions

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

Vitamin B12 has 29 documented interactions across the FDA labels and fact sheets we index: 0 major, 20 moderate, 9 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.

Interactions from the label

Moderate interactions (20)

  • Alogliptin and metforminDPP-4 inhibitorModerate

    Vitamin B 12 Deficiency In metformin 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 patients. (Alogliptin and metformin label, Warnings and precautions)

  • Dapagliflozin and metforminSGLT2 inhibitorModerate

    Vitamin B12 Deficiency In controlled clinical trials of metformin of 29-week duration, a decrease to subnormal levels of previously normal serum vitamin B 12 levels, without clinical manifestations, was observed in approximately 7% of patients. (Dapagliflozin and metformin label, Warnings and precautions)

  • 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)

  • Glipizide and metforminsulfonylureaModerate

    Vitamin B12 Levels: In controlled clinical trials with metformin of 29 weeks duration, a decrease to subnormal levels of previously normal serum vitamin B 12 , without clinical manifestations, was observed in approximately 7% of patients. (Glipizide and metformin label, 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)

  • Linagliptin and metforminDPP-4 inhibitorModerate

    Vitamin B 12 Deficiency In metformin 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. (Linagliptin and metformin 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)

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

  • OctreotideModerate

    Change in vitamin B12 levels: Monitor vitamin B 12 levels during treatment ( 5.6 ). (Octreotide 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)

  • Omeprazole and sodium bicarbonateproton pump inhibitorModerate

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

  • PemetrexedantimetaboliteModerate

    Initiate supplementation with oral folic acid and intramuscular vitamin B 12 to reduce the severity of hematologic and gastrointestinal toxicity of PEMFEXY. (Pemetrexed 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)

  • PralatrexateantimetaboliteModerate

    Administer vitamin B 12 and instruct patients to take folic acid to reduce the risk of treatment-related myelosuppression [see Dosage and Administration ( 2.1 )]. (Pralatrexate 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)

  • Saxagliptin and metforminDPP-4 inhibitorModerate

    Vitamin B 12 Deficiency In controlled clinical trials of metformin of 29-week duration, a decrease to subnormal levels of previously normal serum vitamin B 12 levels, without clinical manifestations, was observed in approximately 7% of patients. (Saxagliptin and metformin 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 (9)

  • 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)

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

  • 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)

  • RanitidineH2 blockerMinor

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

  • RifapentineantibioticMinor

    Interactions with Laboratory Tests Therapeutic concentrations of rifampin have been shown to inhibit standard microbiological assays for serum folate and Vitamin B 12 . (Rifapentine label, Drug interactions)

Check Vitamin B12 against everything you take. Add your full list; every pair is checked at once.

Open in the checker

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.