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B12 And Metformin

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sue_marie

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My diet and lifestyle are both healthy, my T2 is well-controlled and yet I’ve just been diagnosed with pernicious anaemia caused by vitamin B12 deficiency. Until now (after consulting Dr Google), I had no idea that this is a well-known side effect of long term use of metformin. I’m lucky but for those people who don’t get diagnosed in time, the effects of pernicious anaemia can be horrid.
If deficiencies are found early enough, we can easily boost our diets with B12 supplements to keep our levels healthy - and help keep NHS costs lower. But now, I’ve got to have B12 injections for the rest of my life.

Why isn’t B12 a standard check during our annual diabetes reviews?
Why aren’t we advised by our care teams to take B12 supplements?
Why don’t the makers of metformin do something?
 
It is bad that the risk of B12 deficiency isn’t more generally acknowledged or monitored, and I’m sorry you now have pernicious anaemia as a result. I wouldn’t have known about it but for this forum. As a result of reading about it here I started taking a vitamin b complex quite early after diagnosis hoping that’ll help me.
I hope you feel better having the injections.
 
I think that sue-marie is right. There should be a routine test of B12 levels in any patient taking metformin. I would be angry if it was me or anyone I know in this position. Does anyone know if B12 levels are routinely checked in other countries ?
I think this is an important issue.
 
I could be wrong but I think diabetic patients in Germany, once diagnosed, are routinely given vitamin b12 and lipoic acid along with metformin.... I’ve just had a blood test today to check my levels as I’ve been having constant heart palpitations
 
As far as I know we are not routinely tested for B12 levels here in Canada. I do because I always ask for a full blood panel to be taken.....oh, let me tell you, if you are deficient you will know by the extreme fatigue, palpatations, extreme dizziness when bending over...get your B12 injection and literally within minutes you can feel/see the difference. I took injections for a number of years and now take it orally and works well. B12 is important for getting our red blood cells out there and working, so low B12 levels can give a brain fog type of feeling as well - sometimes one's iron (hemoglobin) level will be low so good to get that checked. Cheers/L
 
This is from Jenny Ruhl's website :

"Metformin May Deplete Vitamin B-12 and Folate
Metformin has one more significant side effect. It may deplete Vitamin B-12 because it may alter the ability of the body to absorb vitamin B-12 from the gut. If this is the case, oral supplementation will not help. You would need to have Vitamin B-12 shots to address this deficiency.

Typically it takes about 10 years for low Vitamin B-12 levels to develop, but if you are already marginal for Vitamin B-12 or have other issues with your ability to absorb nutrients this might happen earlier. Your doctor should periodically test your Vitamin B-12 levels if you are taking Metformin.
Low vitamin B-12 causes a form of neuropathy that can be confused with diabetic neuropathy but which is something different.

Effects of short-term treatment with metformin on serum concentrations of homocysteine, folate and vitamin B12 in type 2 diabetes mellitus: a randomized, placebo-controlled trial.Wulffele MG, Kooy A, Lehert P, Bets D, Ogterop JC, Borger van der Burg B, Donker AJ, Stehouwer CD.J Intern Med. 2003 Nov;254(5):455-63."

You can read the whole of her article on Metformin here: http://www.phlaunt.com/diabetes/14045911.php
 
Hi, irregular heartbeat can also be caused by magnesium deficiency, sometimes happens when on a low carb diet.
 
Could I try to untangle something here to make sure everyone is on the same page.? The following is taken from references and is not medical advice or opinion.
The cause of low B12 due to Metformin is unknown, according to diabetesselfmanagement.com.
In contrast pernicious anaemia (PA) is caused by antibodies attacking certain cells in the stomach which produce a substance called intrinsic factor. IF apparently is needed to enable B12 to be absorbed in the last part of the small intestine. (see webmd.com - What to know about Vitamin b12. and percious-anaemia.org )So B12 injections are the usual treatment.
But tests for PA are not 100% accurate. (pernicious-anaemia.org)
Webmed lists other causes of low B12 as infestation with fish tapeworm ( from eating raw fish) and malabsorption of B12 due to coeliac disease, Crohn's disease and bacterial infections and, as was mentioned in another quote, diets deplete in B12 such as a vegan diet (if not supplemented by addition of B12). There are some thyroid and lupus conditions also show up as possible causes.
Also to note is that usual serum B12 blood tests in pregnancy are not necessarily accurate. (active-B12.com)
 
Bigbumcooper said:
How would you know if you were deficient? His would you feel?
Click to expand...
I was diagnosed b12 deficient before the diabetes and I can honestly say that you feel awful, no energy, really lethargic, headachy, dizzy plus I struggled to breathe which I thought was my asthma, I now have 13weekly injections & iron tablets, hope this helps
 
Firstly, I found I'd got low B12 by reading posts on this forum and asking for a test. The patient leaflet that comes with metformin says that 1 in 10000 will suffer because metformin blocks the absorption of B12. If you visit the Pernicious Anaemia Society forum, you will find that most people need regular injections to keep the B12 level up and that doesn't work wonderfully, I found. My GP was very supportive and I ended up on bi-monthly injections when NICE recommend every three months. My personal story was that I decided to get myself off metformin by the LCHF diet and nine months later, the doctor agreed according to my lower HbA1C. I'm now only on gliclazide and maintaining LCHF and my B12 levels are fine without the need for injections (which aren't particularly pleasant, either!) Hope this helps . . .
 

I have my B12 checked within my diabetes review, luckily mine was way over what I needed. Guess its another example of postcode lottery
 
Thanks for your info Kitedoc but I still believe the possible link between metformin-B12-pernicious anaemia needs to be looked at more seriously.
In the same section on Webmd you referred to, it says “The reason this [low B12] happens is often due to the lack of a stomach protein called “intrinsic factor” (IF). Your body can’t absorb vitamin B-12 without it.... Some medicines, like antacids or drugs that treat type 2 diabetes, can make it harder for your body to absorb enough B-12.”
As I have no other illness apart from T2 (and now PA ), am not a vegetarian and there is no family history of PA, I assume that long term metformin could well be the reason my body’s intrinsic factor (IF) has been destroyed and consequently affected my B12 levels. Hence my concern that B12 should be routinely checked for metformin users.
 
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My B12 levels plummeted as soon as I started on Metformin 5 years ago. However, I take B12 as a spray. The vitamin absorbs through the mucosal membranes of the mouth thereby bypassing the uptake system in the intestine. My blood levels, although still low are slowly improving.
 
Is that better than B12 sublingual tablets
 
Haven't heard about sublingual tablets. Can you get them on the NHS?
 
Bigbumcooper said:
How would you know if you were deficient? His would you feel?
Click to expand...
You feel like absolute s***e. I first knew there was something wrong when I began to struggle getting up the stairs at home when I normally ran up them. I felt deep fatigue and muscle weakness. When I started to struggle to unscrew the tops of jars because my arms were too weak, I decided it was time to see my GP. Severe depression/total apathy can also be a symptom,as can tingling and numbness in fingers and toes. Fortunately I have a GP who is a top class diagnostician, and he was the one who thought to test me for B12.
I've had two isolated incidents of B12 deficiency and in both cases I had a course of injections which seemed to see it off. I think mine was due to dietary issues. I'm prediabetic so not [yet] taking metformin.I'll be on extra alert for the B12 problem if I ever do have to go on metformin.
 
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