Anyone heard of B12 deficiency when taking metformin?

[zoombapup]

I was watching a youtube video of Dr Ken Barry and he just posted a video saying that if you're on Metformin you should be taking vitamin B12 supplements to help with some side effects of that drug to do with nerve damage.

Anyone heard anything about this? Seems like if there's really a problem with so many of us on metformin that maybe we'd have heard? Or maybe you guys have and I'm the one in the dark 😉

Just wondering if there's really any advice out there about this.

 

[Drummer]

Metformin is well known for causing B12 deficiency - but my doctor did not bother to mention any possible problems at all.

 

[Greymouser]

B12 deficiency is a very bad thing, please do not ignore, it killed my grandfather, indirectly. I believe a lot of Vegans have issues around B12 too, if they do not take care.

 

[NotWorriedAtAll]

This is very interesting. About twenty years ago I was prescribed Metformin because I was diagnosed with PCOS.
I was on it for four or five years and towards the later part of that time I started getting numbness around my big toes.
I thought it was because I was wearing sandals that were pinching my feet but even though I improved my choice of footwear the numbness remained and I still have it. When I say numbness it is more like a slight pins and needles/tingly feeling.

I came off the Metformin because I couldn't see any real benefit and I was off it from then on until I was prescribed it again and took it for a very short time at the beginning of this year.

And my weird feelings in my feet are still exactly the same as they were back then and have not got worse in any way - which makes me feel it is unlikely to be diabetic neuropathy because I wasn't diabetic back then and even when I was diagnosed at the beginning of last year it was after a six month period of high stress, a surgical procedure, a wedding in Scotland and a bad dose of the flu and Christmas and my HbA1c was 67. Three months later I'd got it down to 55 just by changing my carb intake and the last two times my HbA1C was 42.

So the B12 thing causing neuropathy makes a lot of sense.

Nobody ever mentioned to me there could be side effects like this.

 

[NotWorriedAtAll]

My understanding is that as B12 is in meat, fish, eggs and dairy products this would only be an issue for vegans?

Martin

Turns out that Metformin interferes with the body's ability to access the B12 in meat, fish, eggs and dairy - so it is more of a problem with vegans but still a potential problem with omnivores.

 

[Eddy Edson]

Long-term Met use increasing risk of vit B12 deficiency is well-known but screening doesn't seem to have made it into national guidelines, for some reason.

 

[Greymouser]

There is loads out there on the internet about B12 deficiency, here are a couple:
https://www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/causes/
https://pernicious-anaemia-society.org/b12deficiencyandperniciousanaemia/

From the second one:

The following leads to the patient’s B12 being compromised in some way and to some degree or other:

• Contraceptive Pill
• Ibuprofen (pain killer)
• Colchicine (used to treat gout)
• Cimetidine (used to treat peptic ulcers)
• Omeprazole and Lansoprazole (proton pump inhibitors)
• Phenobarbital, Pregabalin, Primidone and Topiramate (epilepsy)
• Metformin (Type 2 Diabetes)

There are other medicines that can cause it too and it is not just vegans who have issues with it. My wife's' aunty has it and is very much a meat eater, but is quite elderly, which is another possible cause, as our bodies fall apart. She is also on quite a lot of medication.

 

[Toucan]

I heard about this a while ago, and asked for a B12 check to be include in my blood test. It showed up as normal.
As @Anitram says, there are good sources of B12 in fish, meat, poultry and dairy.
It is said to be high in spinach, mackerel and some cheeses such as parmesan, feta and mozzarella.

 

[zoombapup]

I ordered myself a years supply of B12 supplement for a fiver on Amazon. Because I already wanted to put in an order for some curry paste and needed to up the order a bit anyway 🙂 I'm guessing that there's lots of little side effect nasties in all this wonderful medicine I'm taking. You'd think people prescribing it would at least mention the potential for issues.

 

[Grannylorraine]

Mentions it on the patient information leaflet under side effects. I am certain that my doc has sent me for a blood test to check that, but it might have been B6 that was checked.

 

[grovesy]

It is recommended if you are on Metformin to have B12 checked. I have mine done annually.

 

[Kopiert]

When I was on Metformin my doctor detected a drop in B12. It was never mentioned as side effect at the point of prescription. I was put onto a course of B12.My levels came back to normal when I stopped taking Metformin. My new GP said it is highly likely the Metformin was the reason.

 

[everydayupsanddowns]

Yes B12 does seem to take a bit of a hammering in some people taking Metformin, but from reading others’ experiences, like many diabetes things, it seems a bit variable and to affect some people a lot and others not at all.

 

[Neens]

It is well documented. I discovered it in the Learning Zone here, I think. I asked my DN on my 2nd apt. (about 4 weeks after starting metaformin on diagnosis) she told me not to worry. I still do a bit.