Metformin is a widely prescribed medication for the treatment of Type 2 diabetes. It is a relatively safe and very effective means of controlling blood sugar, though persons taking this medication may be on it for life. Recently a new study from China found that metformin users may be at risk for a deficiency in Vitamin B12. The report was published in the October issue of Archives of Internal Medicine.
Vitamin B12 is a necessary vitamin for many functions in the body including the production of DNA and for proper nervous system functioning. A deficiency in Vitamin B12 can result in conditions such as megoloblastic anemia and peripheral neuropathy.
For the study researchers analyzed Vitamin B12 status in diabetic patients who were either on metformin or not. They found that the use of metformin statistically effected the Vitamin B12 status.
Individuals who had been using a 1000 mg dose of metformin had more than twice the risk of having Vitamin B12 deficiency compared to non-users. Those that had been taking the medication for long term, greater than 3 years also had double the risk compared to non-users regardless of the dose.
The lead authors suggests that all individuals taking metformin to treat Type 2 diabetes be screened for a Vitamin B12 deficiency. For those taking a higher dosage or who have been taking it long term screening is even more important.
Supplemtation with Vitamin B12 should not effect the performance or efficacy of metformin for treating Type 2 diabetes. Though this study does not recommend it, supplementation may become a recommendation for any person on metformin in the future.
Posted by Dr. Christina Gutierrez on November 6, 2006 02:47 PM
