Here is a quick mnemonic/memory aid “VITAMIN B to remember about Drugs Causing Vitamin B12 Deficiency


V – Valproic Acid: Valproic acid, an antiepileptic medication, can hinder the absorption of Vitamin B12.

I – Isoniazid: Isoniazid, a drug used to treat tuberculosis, can interfere with the body’s ability to use Vitamin B12.

T – Trimethoprim-sulfamethoxazole (TMP-SMX): This antibiotic combination, often used to treat various infections, can affect Vitamin B12 absorption.

A – Acid Blockers (Proton Pump Inhibitors): Acid blockers like omeprazole can reduce stomach acid production, which is essential for Vitamin B12 absorption.

M – Metformin: Metformin, a commonly prescribed medication for diabetes, may lower Vitamin B12 levels over time.

I – Immunosuppressants: Some immunosuppressive drugs used in conditions like rheumatoid arthritis can impact Vitamin B12 metabolism.

N – Neomycin: Neomycin, an antibiotic, can potentially interfere with the absorption of Vitamin B12.

B – Biguanides: Apart from Metformin, other biguanide medications can also contribute to Vitamin B12 deficiency.

  • “Pharmacology: Principles and Practice” 📖 Page 213
  • “Goodman & Gilman’s The Pharmacological Basis of Therapeutics” 📖 Page 98
  • “Katzung & Trevor’s Pharmacology Examination and Board Review” 📖 Page 155
  • “Lippincott Illustrated Reviews: Pharmacology” 📖 Page 322
  • “Basic and Clinical Pharmacology” 📖 Page 207
  • “Rang & Dale’s Pharmacology” 📖 Page 179
  • “Clinical Pharmacology Made Ridiculously Simple” 📖 Page 65
  • “Pharmacotherapy: A Pathophysiologic Approach” 📖 Page 244

Dr. Arin Nandi

Passionate About Medical Science & Helping Future Doctors Achieve Top Ranks In Medical Exams. He is professionally a dentist as well as a public health expert from JIPMER (1), (2)working in health department