Diabetes Drug Metformin Linked To Vitamin B12 Deficiency
By Mike Boyle

Diabetics treated over long periods with the commonly used drug metformin are at risk of developing a vitamin B12 deficiency which is also likely to get worse over time, according to a new study conducted by Dutch researchers.

The findings of the study, published in the British Medical Journal suggest that regular checking of vitamin B-12 levels during long-term metformin treatment should be "strongly considered" to try to prevent deficiency and its effects.

As Reuters stated in reporting news of this study, "vitamin B12 is essential to maintain healthy nerve cells and red blood cells. It is found in meat, dairy products, eggs, fish, shellfish and fortified breakfast cereals, and it also can be taken as a supplement."

Coen Stehouwer of Maastricht University Medical Center in the Netherlands and one of the study`s researchers, said symptoms of B12 deficiency include fatigue, mental changes, anemia and nerve damage (neuropathy).

Those symptoms can easily be misdiagnosed as being due to diabetes and its complications, or to aging, Stehouwer added, but checking B12 levels could help doctors to assess the real cause and treat it if it was found to be B12 deficiency.

"Our data provide a strong case for routine assessment of vitamin B12 levels during long term treatment with metformin," Stehouwer wrote in the study.

The research team studied 390 patients with type 2 diabetes, giving metformin to 196 of them three times a day for more than four years, and a placebo to the other 194.

They found that people who had taken the metformin had a 19 percent reduction in their vitamin B12 levels compared with people who had taken a placebo, who had almost no B12 change.

Read a full text of the metformin/B12 study here.

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Originally posted May 21, 2010.