Drugs That Cause Vitamin B12 Deficiency

What is Vitamin B12?

Several drugs can cause vitamin B12 deficiency. This is important to recognize since vitamin B12 is necessary for the healthy development of all cells in the body. Vitamin B12 goes by other names like methylcobalamin, cyanocobalamin, and hydroxycobalamin and plays a critical role in the formation of red blood cells and the production of myelin. Myelin is the covering or insulation of nerve cells (including those in the brain). Vitamin B12 deficiency is associated with brain shrinkage and memory/psychiatric disorders.

Vitamin B12 can be obtained by eating foods like meat, fish, dairy products, and foods fortified with B12.

Vitamin B12 Deficiency Caused by Drugs

There is a host of drugs that can cause vitamin B12 deficiency. Not only that, but many of them are prescribed frequently for some of the most common medical problems making vitamin B12 deficiency a real possibility for many patients. Many antibiotics can affect B12 levels when used for prolong periods. Bacteria in the gut help to manufacture vitamin B12. Antibiotics can interfere with these healthy B12 producing bacteria.

Below is a list of antibiotics and other drug classes that cause vitamin B12 deficiency.

Antibiotics that Cause Vitamin B12 Deficiency

• Penicillins
• Cephalosporins
• Fluroquinolones
• Macrolides
• Aminoglycosides
• Tetracyclines
• Sulfonamides
• Neomycin

Other Drug Classes that Cause Vitamin B12 Deficiency

• Phenytoin (anticonvulsant)
• Metformin (diabetes)
• Colchicine (gout)
• Antiviral drugs
• Bile acid sequestrants (cholesterol-lowering drug)
• Birth control pills
• H-2 receptor antagonists (ulcer drugs)
• Proton pump inhibitors (ulcer drugs)

Within the ulcer drug classes are several drugs. Below are their generic names and brand names in parentheses. These drugs reduce the secretion of gastric acid and pepsin which unfortunately lowers the absorption of B12 from dietary sources but not supplemental B12. Many of these drugs can interfere with the absorption of other vitamins and minerals for the same reason.

• Cimetidine (Tagament)
• Ranitidine (Zantac)
• Famotidine (Pepcid)
• Nizatidine (Axid)
• Lansoprazole (Prevacid)
• Omeprazole (Prilosec)
• Pantoprazole (Protonix)
• Esomeprazole (Nexium)
• Rabeprazole (Aciphex)