Source: American Diabetes Association’s 69th Annual Scientific Sessions.

A study presented in June 2009 at the American Diabetes Association’s 69th Annual Scientific Sessions, looked at the prevalence of vitamin B12 deficiency in 76 people with type 2 diabetes who had been taking Metformin for at least one year.

The results showed that more than 75% of Metformin users who had low vitamin B12 levels also had evidence of peripheral neuropathy. Researcher Mariejane Braza, of the University of Texas Health Science Center, and colleagues say that the number of people with peripheral neuropathy in the vitamin B12 deficiency group was surprising.

They say it’s not clear whether vitamin B12 deficiency may contribute to or cause peripheral neuropathy. But they recommend screening Metformin users for vitamin B12 deficiency and supplementing the vitamin, when necessary, to reduce the risk of nerve damage