There is a connection between diabetes medication Metformin and Vitamin B12 deficiency, this article talks about the best steps for you to take to address this.
How to identify and resolve B12 deficiency
How to improve blood sugar levels so maybe you don’t need diabetes medication (never stop medication without your doctor’s approval).
Evidence suggests that metformin lowers vitamin B12 levels and raises homocysteine levels in patients with type 2 diabetes
Observational studies have suggested that metformin causes vitamin B12 deficiency in some patients; researchers have proposed several possible mechanisms whereby metformin might interfere with B12 absorption.
Understanding this interaction is important because B12 deficiency could exacerbate neuropathic symptoms in patients with diabetes.
A long term study on Metformin and Vitamin B12 deficiency showed low levels of B12 and increased levels of anemia after the 5 year study. The longer participants took Metformin the increased risk of Vitamin B12 deficiency and neuropathy symptoms.
In a prospective case-control study, Canadian investigators identified 122 type 2 diabetic patients with peripheral neuropathy:
Half had taken metformin for at least 6 months, and half had never received metformin. Otherwise, the clinical characteristics of the groups were similar.
Median serum B12 level was significantly lower in the metformin group than in the no-metformin group (231 vs. 486 pmol/L). Metformin recipients also had significantly higher levels of homocysteine and methylmalonic acid (markers of B12 deficiency) and significantly worse scores on standardised clinical assessments of the severity of neuropathy.
In multivariate analyses controlled for age, duration of diabetes, and glycosylated haemoglobin (HbA1c) level, metformin therapy was associated independently with worse neuropathic symptoms.
This study strengthens the case for an effect of metformin therapy on vitamin B12 levels. The analysis also suggests that this interaction worsens neuropathy, but confounding by unknown factors could be responsible for this observation. In one randomized placebo-controlled trial, metformin lowered B12 levels (J Intern Med 2003; 254:455)
In another study Wile DJ and Toth C. Association of metformin, elevated homocysteine, and methylmalonic acid levels and clinically worsened diabetic peripheral neuropathy. Diabetes Care 2010 Jan; 33:156.
So there is plenty of evidence showing that Metformin and Vitamin B12 deficiency is a problem, especially with long term use of Metformin and this is a drug that is usually taken “forever” once it is prescribed
The first thing to do is to get your vitamin B12 levels tested so that you have a baseline reading, don’t follow the reference range but make sure your levels are over 400 as a minimum.
The Vitamin B12 Guide goes into a lot more detail about the best ways to test, prevent, and treat Vitamin B12 deficiency.
I would also recommend testing homocysteine levels, elevated homocysteine is associated with both a Vitamin B12 and folate deficiency. High homocysteine is a cause of cardiovascular disease and Alzheimer’s so you don’t want your diabetes medication to increase the risk of other health problems.
Plus diabetes is an independent risk factor for Alzheimer’s.
There are a lot of quality Vitamin B12 supplements out there (and also a lot of bad ones) and the key is to get your supplements from a quality brand in the active form that you need.
I prefer sublingual Vitamin B12 lozenges over capsules as they are better absorbed, especially for people with digestion problems or low stomach acid (which many old people have).
There are a couple of good options for sublingual Vitamin B supplements and one of my favorite brands is Seeking Health as you get to choose from a number of different B12 combinations.
For specific recommendations check out the Vitamin B12 Guide.
The first thing that I need to emphasize is never to stop medication without talking to your doctor.
The second thing is never to stop taking medication without addressing the underlying cause of why you needed the medication in the first place.
If you are taking Metformin because you have high blood sugar levels, you need to first address the cause of the high blood sugar – and the best way to do this is through your diet.
I highly recommend the book The Diabetes Code by Dr Jason Fung as a starting point.
This book will give you the confidence to implement a lower carbohydrate diet and intermittent fasting to reduce your blood sugar levels and diabetes risk.
Following these guidelines, you may eventually be able to stop your medication, but more importantly, stop diabetes and associated health problems from getting worse.
*Metformin has been associated with a longer lifespan so many healthy people have started taking this drug, but if you are healthy you may not get the benefits and it can have other negative consequences like reduced benefits from exercise.
Michael is head consultant at Planet Naturopath - Functional Medicine and Nutrition Solutions. He is a registered naturopath with the Australian Natural Therapists Association (ANTA) and works with clients from all over the world via video or phone consultations. He is a degree qualified naturopath from the Endeavour College of Natural Medicine in Australia with 18 years of experience. He uses advanced testing methods, nutritional medicine, herbal medicine, and lifestyle advice to help you stay healthy. He is a Kalish Method-trained practitioner that keeps updating his education with Chris Kresser. Michael completed Dr. Terry Wahls practitioner training program, a 12-month program with ongoing training that helps understand the underlying cause and treatment of MS and autoimmune conditions. He keeps up to date with the latest research into health and natural medicine through the Metabolic Fitness Pro course with Dr. Bryan Walsh.