Metformin Plus GERD Meds Can Lead to B12 Deficiency, Neuropathy

Metformin is the most commonly prescribed diabetes medicine in the world, with more than 61 million prescriptions filled in the United States alone in 2012. Now, a new report from West Liberty University indicates that using this drug along with certain classes of medicine for gastroesophageal reflux disease (GERD) can lead to vitamin B12 deficiency and subsequent neuropathy, or nerve damage (an often painful condition that affects up to 70% of people with diabetes).


More than 40% of the 29 million people in the United States with diabetes also have GERD, and 70% of that population uses oral diabetes medicines such as metformin, making it likely that millions of people are using both GERD and diabetes drugs simultaneously. Both metformin and acid-suppressing GERD medicines from classes known as histamine H2-receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) have the potential to cause vitamin B12 deficiency, which can lead to the development of neuropathy.

In reviewing studies on metformin, H2RAs, PPIs, and vitamin B12 deficiency, researcher Matthew J. Zdilla, DC, found that using both metformin and one of the GERD medicines was likely to further increase a person’s chances of developing vitamin B12 deficiency and resulting neuropathy beyond the risk of using just one of these medicines.

“Pharmacists, clinicians, and patients need to be aware of the potential for…B12 depletion [caused by the simultaneous use of multiple medicines] and the potential for subsequent neuropathy,” notes Zdilla. “Awareness is particularly important because metformin and acid-suppressing medications are commonly used in the diabetic population, which has a high prevalence of neuropathy.”

Zdilla referenced a variety of studies in which vitamin B12 either taken by mouth or through an injection was found to improve the symptoms of neuropathy in people with diabetes, suggesting that their conditions were due, at least in part, to B12 deficiency neuropathy rather than diabetic neuropathy.

For more information, see the article, “Metformin Plus GERD Medications Diminish Vitamin B12,” or see the report in the journal Clinical Diabetes. And for more information on the association between metformin and vitamin B12, click here.

Do you have diabetes and live in Kansas? Then be sure to bookmark and tune in tomorrow to learn about the upcoming “Taking Control of Your Diabetes” health fair in Overland Park.

Learn more about the health and medical experts who who provide you with the cutting-edge resources, tools, news, and more on Diabetes Self-Management.
About Our Experts >>


    excellent information. I’ve been supplementing with either B complex or B12 for years to help with fatigue. Has anyone suggested a dosage effective to reduce neuropathy?

  • Yankle Ruben Austin

    I have Diabetes as well as GERD but also Neuropathy, Degenerative Disc Disease, Degenerative Arthritis, Degenerative Nerve Damage, Tourette Syndrome, Sleep Apnea, INSOMNIA, NARCOLEPSY, Depression, Mood Swings, High Blood pressure, RLS & RSDS plus other issues and I take about 30+ meds mostly in pill form. It makes me wonder if my Conditions are all affected by each other and all the different Meds I have to take just to Function. Missing just 1 individual dose of any one Med causes my body and Mind to just Shut Down. I wish there were studies that I could attend to see if there are any direct relationships between the Disabilities and Meds I have to take.