Pernicious Anaemia Society

B12 and the heart

I have PA and take B12 losenges and Ia few weeks ago, decided to give my husband one a day for a couple of weeks to top up his B12. He hadn't had a blood test, it was just me thinking it might be a good idea. He had a little bit of tingling in his little finger, but no other real symptoms . We are both 61.

For the last year he has suffered from an irregular heartbeat and atrial fibrillation. His heart rate can go up to 150 a minute during an episode which can last for seconds or hours. He has an Alivecor and uses a Fitbit to keep a check on it as he drives for a living.

Since taking B12 is heart has been steady as a rock - no irregularities, no atrial fibrillation, just a steady, normal heartrate which steadied within a couple of days of taking B12 under the tongue.

I can't find any link to PA or B12 deficiency linked to atrial fibrillation anywhere, although logically, AF is a problem with the nerves of the heart rather than the heart itself, so it would make sense (if only to me!).

There has been no other changes that we can think of that would account for this and we've analysed everything. The only change has been his regular intake of 1000 B12.

His father has PA and has monthly injections, although I'm not sure whether its inherited or not.

My husband is somewhat bemused but very pleased. Does anyone know of any link just so that we are not imagining this.

Many thanks.

9 Replies

"His father has PA and has monthly injections, although I'm not sure whether its inherited or not."

It can run in families. If there is PA in his family, I am surprised he has not been tested for PA.

I found it helpful to contact the PAS (Pernicious Anaemia Society). If you leave a message they should get back to you within a few days. You do not have to be a member to phone them.


01656 769 717


Sometimes supplementing with B12 prior to being tested can make it difficult to get a diagnosis because it can affect the results. As an absolute last resort I started to treat myself after I failed on several occasions to get B12 treatment on NHS. This however has made it impossible to get a diagnosis.

See link below for tests that can help to diagnose B12 deficiency. Has he ever had an IFA (Intrinsic Factor antibody test) which can help to diagnose PA. However the IFA test is not totally reliable and people who test negative may still have PA.

Rest of website has lots of useful info.

Has your husband had recent tests for folate, B12, ferritin and a FBC (Full Blood Count)?

There can be useful clues on a FBC as to whether B12 deficiency is a possibility. High MCV and high MCH indicate the possibility of macrocytisis (enlarged red blood cells) which is sometimes found in B12 deficiency.


Has your husband got any other symptoms? B12 Deficiency can develop very gradually so people may put changes down to getting older.

See section on "Vascular Problems"


See Symptoms Checklist


"Could It Be B12" By Sally Pacholok and JJ. Stuart

Very comprehensive book about B12, lots of case studies.

"What You Should Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper


There can be many causes of B12 deficiency. See link below.

Useful websites

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Many thanks Sleepybunny. His father has enlarged blood cells and turned yellow before he was finally diagnosed aged 80 and six years later, on the injections is now fine and is out and about every day. I didn't know it could be inherited.

My husband has never had any tests, I've just checked his paperwork, except liver function tests for the drugs he was on. He's off all of them now except an anti-coagulant.

He gets numbness and tingling in his hands, moreso when he's actually in AF. He's had feelings like electric shocks for many years.

Last year a cardiologist told me that doctors are not interested in the cause of ill health, they only deal with symptoms. At that moment I lost all confidence in the medical profession and only use them when I've run out of other options, so I don't know what his ferritin, folate or B12 levels actually are. To be honest, neither of us want to go into battle to try to get them either.

If this has been caused by PA or even a deficiency of B12 I am going to be furious that these tests weren't done a year ago when he was in hospital with a racing heart that never responded to their drugs. He was sent home with his heart still racing, exactly as it was when he was ambulanced in five days before.

Hence my query as to whether atrial fibrillation could possibly be another less well known symptom of PA. I guess if he stays on the B12 losenges and has no further recurrence of AF we will have our answer.


I hope he gets the answers he needs.

Untreated or inadequately treated B12 deficiency, whatever its cause, can lead to permanent neurological damage.

The BNF (British national formulary) Chapter 9 section 1.2 which all GPs have access to and the BCSH Cobalamin and Folate guidelines give guidance on treatment of B12 deficiency. I found page 29 in the BCSH Cobalamin Guidleines, a diagnosis and treatment flowchart, useful.

PA treatment includes B12 injections for life.

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Hi Davesgirl.

I've been on b12 injections for nearly 45 years and never had AF so perhaps your "experiment" explains that - and that's not me being being flippant...

I wish both you and your husband well for the future.

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I have always had heart arrhythmia issues and had an op nearly 20 years ago to stop the tachycardia I was getting but it didn't solve the other problems I had with it. In the last few years I was getting heart failure symptoms too.

I have always had some B12d symptoms and my heart has been worse when they are. Now if I get enough B12 and supporting supplements my heart is fine.

I'm sorry you have been made to doubt what you know is sensible and true. People on here will genuinely listen and treat you with the respect you deserve as we're all "in the same boat"!


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The NHS itself describes how heart problems can result from low B12:

However, if you are tested and your result falls within their "normal" range they will not see that as a cause (even if it actually is).

You can get the tests mentioned by ordering them online (you have to pay for them of course) if you don't want to go through the GP but they will not be accurate now he is supplementing.

However, it's great that you've found out the supplements help. I hope they continue to do so.

Re: "a cardiologist told me that doctors are not interested in the cause of ill health, they only deal with symptoms" I asked my GP recently about finding the cause of an illness (in order to get the correct treatment) and they said I was "asking too much". In my opinion, correct diagnosis is crucial, and surely what medicine is, or should be, really about.

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Many thanks for all your helpful replies. I really appreciate it. We will continue to research this and see what happens. Thank you again.

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I have read that it is important to take a good B complex when taking B12 lozenges - to keep all the B's in balance.

Low Iron - Ferritin - Folate can also be a problem for the heart as others have mentioned.

Blue Horizon enable you to have tests done privately - and in the home with a finger prick - could be worth investigating.

I had heartbeat problems before being diagnosed with Hashimotos in 2005 - auto-immune thyroid condition. The thyroid has a huge impact on the heart - both too much and too little T3. There is a book on Amazon called - Thyroid and Heart Failure - where Endocrinologists and Cardiologists came together in the name of research - for the first time I believe. You can look inside the book and read some pieces.

Hope hubby continues to flourish :-)

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That's interesting Marz. I will check out Blue Horizon. Thank you.

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