Metformin Without Vitamin B12 May Impair Cognition

I am a little surprised at this study, as I have been aware of this for some time and knew that metformin caused Vitamin B12 deficiency. I also knew that Vitamin-B12 deficiency could cause cognition problems in patients. Now a new study from Australia suggests, repeat, suggests this may be true. Yes, there have been some conflicting studies previously, but apparently, this study can only suggest this being the case. This tells me this study missed some important points or was incomplete in the data collected.

Lead author Eileen M. Moore, PhD, a medical research scientist in the department of surgery, Deakin University, Geelong Hospital, Barwon Health, Geelong, Australia, says, “Up to 30% of patients taking metformin may be deficient in B12, and this is thought to be due to an interaction between metformin and a receptor in the distal ileum, leading to some inhibition in the uptake of the vitamin.”

She continued, "Metformin remains a very effective first-line antidiabetic drug and may reduce cardiovascular risk in patients with diabetes. Clinicians and patients should not be alarmed by these findings, but the need to monitor and correct vitamin-B12 levels is highlighted."

At least she understands how important her last statement above is and that doctors with patients on metformin need to be tested for vitamin B12 deficiency. Dr. Moore recommends "Clinicians should consider monitoring cognition in [all] patients over the age of 50 years who use metformin, especially when there are other risk factors for dementia present. Because current treatments for dementia are palliative only, intervention in the early stages of cognitive decline remains the best option.”

This is important in the United States because many doctors do not and will not test for vitamin deficiencies as they believe in the medication route only and that we should obtain our vitamins and minerals from a well balanced diet only. What these doctors do not understand is that with metformin, even patients on a well-balanced diet have malabsorption of vitamin B12 and this leads to the deficiency.

Even with this problem, people with diabetes have a link to dementia without metformin, so it would be wise to test all patients for vitamin B12 deficiency and to be concerned about dementia.