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B12 intake cause of my sudden symptoms of hyperthyroidism?

Seahorse76 profile image
15 Replies

Could high oral B12 intake (1000-2000mcg/day) cause hyperthyroidism? I noticed from recent blood work that my serum B12 was lower than it used to be: currently at 344 pmol/L for a range between 150 to 600 pmol/L. It used to be 732 pmol/L in 2018. I was diagnosed with Chronic Fatigue Syndrome last March, and suffer from symptoms that might suggest I need a boost of B12: extreme exhaustion, depression, anxiety, constantly catching colds or even flus, and feeling of weakness in my legs. So, 4 days ago I began supplementing with B12 and I immediately felt like I had “just woken up after a very long nap”, like a magical switch after many years of progressive debilitating condition. Now, I understand that my initial reaction to B12 was possibly sychosomatic, as it takes a while for it to work. However, since starting the B12 5 days ago, I have started to suffer from symptoms of hyperthyroidism. Could B12 intake cause hyperthyroidism? Really feeling poorly and can’t even sleep.

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Seahorse76
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15 Replies
JanD236 profile image
JanD236

I’m not a medical professional but I’ve never heard that high B12 intake could cause such symptoms.

However, I would mention that autoimmune illnesses often come in clusters. For example, I have Graves’ disease (hyperthyroidism), PA and vitiligo. So antibody testing is what I’d be asking my GP to consider.

Seahorse76 profile image
Seahorse76 in reply toJanD236

Thank you so much for your reply JanD236. I forgot to mention that I was diagnosed with Hashimoto’s in 2009, with elevated TSH and antibodies above range for the anti-thyroglobulin, but not for TPO’s. I was treated for a year and a half with synthroid. However, my hypothyroidism became hyperthyroidism and I had to stop the treatment and take anti-thyroid medication for a few months. I haven’t been treated ever since. I check my thyroid every year through blood test, but since my tsh is always great, I never have the possibility of testing T3 or T4. Every year, I have 1 or 2 episodes of hyperthyroidism lasting at most 3 days but this time it has been more intense than I remember it to be. I agree with you, I should ask the doctor for antibodies testing.

JanD236 profile image
JanD236 in reply toSeahorse76

And a full thyroid panel too given your history.

Seahorse76 profile image
Seahorse76 in reply toJanD236

That’s a good idea too, for sure.

Marz profile image
Marz in reply toSeahorse76

If you were diagnosed with Hashimotos then it is possible to swing between being hypo and hyper. Taking the anti-thyroid drugs did sound drastic. Do you have your results from that time ? Was the T3 tested ?

Seahorse76 profile image
Seahorse76 in reply toMarz

Hi Marz. Thank you for your message. I know it seems unlikely to need anti-thyroid medication for Hashimotos. I moved from France to Canada in 2010. Upon my arrival, I developed weird symptoms that I attributed to anxiety and this for over 6 months. Eventually I met with a doctor in a walk-in clinic who took the time to look at my blood test results ( the ones then taken in Canada). He realized that I had been dealing with hyperthyroidism for those 6 months. I had lost a lot of weight then and my heart kept beating faster than I am used to. To answer your questions: I do have my blood test results that showed I have Hashimoto from 2009.

My TSH was then 5.76 mUI/L and the range was from 0.30 to 4.00 mUI/L.

My free T4 was at 11.4 pg/ml for a range between 8.9 to 17.6 pg/ml.

My free T3 was 3.7 pg/ml for a range between 2.0 to 4.4 pg/ml.

My anti-thyroglobulin antibodies were above range at 162.00 UI/ ml ( normal range is less than 115 UI/ml.

My anti- thyroperoxydase antibodies were at 10.16 UI/ml and normal range is less than 34.00 UI/ml.

Finally, my anti TPO was inferior at 1.00 UI and normal range was less than 1.5 UI/L.

When I moved to Canada, I wasn’t able to have directly access to my blood tests until 2014 unfortunately. Otherwise, I would have probably detected the hyperthyroidism sooner.

Seahorse76 profile image
Seahorse76 in reply toSeahorse76

I apologize, I got mixed up on my last result. I meant Thyroid Stimulating Hormone Receptor Antibody instead of anti TPO.

Marz profile image
Marz in reply toSeahorse76

It is also possible to have both Graves and Hashimitos I have read. The results above do indicate you were Hypo as you mentioned. How did the results change when you were Hyper ? Lots of knowledgeable people on the Thyroid UK Forum who will be able to share their experience better than me - I have Hashimotos as well as B12 issues caused by surgery and I self inject ...

It is often mentioned that with Thyroid issues it is good to have optimal levels of B12 - Folate - Ferritin - VitD. B12 around 500 - Folate and Ferritin mid range and VitD at 60 ( if measured in ng/L )

thyroiduk.org

vitamindcouncil.org

grassrootshealth.net

Seahorse76 profile image
Seahorse76 in reply toMarz

I wish I had had access to my blood test results in 2011-2013... I went to walk-in clinics and always saw different doctors. In 2014, I learned I could have access to my blood test directly online by signing up a request form. So I now have access to all my results since 2014 but not from before.

I know that in 2014 my tsh was once at 0.11 mU/L for a range between 0.30 to 5.50 mU/L, but the doctor wasn’t worried. Then the tsh went back to a “normal” level and has been at around 1.61 mU/L since then.

I did check my vitamin D level, which is good at 83.

My ferritin is too low: at 40 ug/L and the doctor I saw last time told me I should aim for 70 ug/L .

I never tested for the folate. I am going to the clinic tomorrow and will request some blood work.

Thank you so much for your help and the links. I did post on the Thyroid UK forum earlier today 😊.

Marz profile image
Marz in reply toSeahorse76

Hope you will soon feel better .. will take a peep at your new post 😎

Seahorse76 profile image
Seahorse76 in reply toMarz

Thank you so much ☺️. I hope so too. I will post my blood results once I get them. I was a bit lazy ( after 3 nights of sporadic sleep), and only copy pasted the same initial message on the thyroid forum but will give more info as requested.

Marz profile image
Marz in reply toSeahorse76

Am hoping greygoose - SeasideSusie and SlowDragon will soon be awake and respond !! It's only 7.30 am here ! Also there are lots of other very informed and helpful people. Check out Greek chick- she is in Canada too ...

Seahorse76 profile image
Seahorse76 in reply toMarz

Thank you for all your support, so deeply appreciated right now. I will definitely check everybody out! 😊

Seahorse76 profile image
Seahorse76 in reply toSeahorse76

It’s 11:36 pm here in Vancouver so I will try to get some sleep 😴 .

Seahorse76 profile image
Seahorse76 in reply toSeahorse76

Just an update as I am back from the doctor: it’s unlikely the B12 caused my symptoms. The doctor thinks I have a flu-like illness as well as an adverse reaction to an anti anxiety medication I started taking 3 weeks ago ( Buspar.)

I did some blood work and having the B12 re-tested and thyroid. I also had an ECG. I will let you know once I get the results.

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