Years Of Taking Popular Diabetes Drug Tied To Risk Of B12 Deficiency

Following participants with a high risk for type 2 diabetes, for more than 10 years, researchers have recently discovered that people who take metformin (a common type 2 diabetes medication) for several years may have a heightened risk of vitamin B12 deficiency and anemia.

Study high lights, from the Reuters article:

  • The study began with more than 3,000 people age 25 years and older with high blood sugar. The participants were randomly assigned to receive either 850 milligrams of metformin twice daily, placebo medication or an intensive lifestyle program than did not include medication.
  • During follow-up, the participants provided blood samples at the five- and 13-year points.
  • Using these blood samples, the researchers found that at year five, average B12 levels were lower in the metformin group than the placebo group, and B12 deficiency was more common, affecting 4 percent of those on metformin compared to 2 percent of those not taking the drug.
  • Borderline low B12 levels affected almost 20 percent of those on metformin and 10 percent of those taking placebo.
  • Average vitamin B12 levels were higher by year 13 than in year five, but B12 deficiency was also more common in both the metformin and placebo groups.
  • More people in the metformin group were also anemic at year five than in the placebo group.

Currently, metformin- which helps to control the amount of sugar, or glucose, in the blood by reducing how much glucose is absorbed from food and produced by the liver, and by increasing the body’s response to the hormone insulin- is the most commonly used drug to treat type 2 diabetes(among other illnesses). However, the Sr. author of the study doesn’t feel that the B-12 deficiency should prevent people from taking it. Rather, they should ask their doctor to routinely check their levels because prolonged deficiency has been linked to anemia, impaired cognition and dementia- yet it is easily reversible with treatment with pills or monthly injections.

If you are a vegan, you’ll likely need to take supplementation as humans don’t make vitamin B12 and therefore need to acquire it from animal sources or supplements (although vegetarians may get enough from eating eggs and dairy products).

Source: Reuters