Pernicious Anaemia Society
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Is it really B12d? Next steps to investigate please!

Sorry, this is going to be a long one!

Starting with med history:

coeliac following a strict GF diet for the last 14 years,

lactose intolerant for last 12 years (I can have very small amounts of cheese),

2011 diagnosed with VitD deficiency - took Adcal for 2 years and now back in reference range so don't have that any longer,

2012 further endoscopy because of fatigue, and possible refractive coeliac - given all clear on small bowel health, put on Low FODMAP diet to relieve IBS symptoms (seemed unable to process carbohydrates). Part of this diet limits most sources of folates, broke the diet on B12d/ folate deficiency dx.

Later 2012 diagnosed with Reactive Hypoglycemia (pre-diabetic), went on a 6 small meals high protein low carb diet, lost 3 stone, started doing triathlons and lost the blood sugar spiking, so no longer RH or pre-diabetic, but I have to keep it in check still.

2014 3 months off work with depression and fatigue.

2014 Diagnosed with B12D and given loading dose 1mg, 6 times over 2 weeks, then 8 weekly jab, adjusted to 4 weekly in Jan 2015, adjusted to 2 weekly last week.

I HAVE BEEN SO TIRED FOR YEARS! Probably started in 2005, though it has got worse and brain fog is a reasonably new addition to the symptoms, maybe since 2012.

I'm having horrible recurrent episodes, such as;

Needing to sleep instantly - needing to stop on the spot, sit for 15 minutes to 3 hours and sleep or rest. I feel locked in when this happens, my body is too tired to move but my brain still functions fine.

Ridiculous fogs - watching the same programme 5 times in 2 days but still not knowing what has happened in it, recalling some of an event but missing chunks, knowing words, sentences, and knowing that I know them but they are just out of reach in my head, making really silly decisions that I wouldn't normally make (i.e., if I pedal backwards my bike will slow down, which I made whilst going 30mph down a hill!)

Cold, freezing to the bone. Only rest warms me up.

Yawning, sighing, particularly on exertion, such as walking downstairs to make a coffee, or walking to the bathroom - needing a big rest after one of these activities.

I take Fluoxitine 10mg daily for depression, which I have had for 2 months now. Took previously in 2014 too. I have 800% of RDI folate daily in tablet form, make sure I eat 1 banana and 1 orange and a handful of almonds daily (potassium, magnesium, more folate). I also take sublingual B12 (Solgar) 2500mg almost daily, more when I feel that I am slipping.

B12 originally made a massive difference. Felt like I had been a sponge before and that the holes were being filled in. HOWEVER, on the last 3 jabs I've had the horrible symptoms listed above for about 2 days before the jab and then felt ok for maybe an hour after the jab, then been back in bed for 3 days. I'm missing 5 days every fortnight and I really can't keep going like this much longer.

Should also say that as an amateur triathlete, I train for around 10 hours a week, as well as teaching full time. Every three weeks of training I find I just have to stop and do nothing. I think I'm quite sensible and don't push myself too far or beyond my capabilities of the moment. But what a contrast between 4 hour endurance events and being unable to walk to the bathroom without needing a nap!

Since I am coeliac I have yearly bloods. GP could see my B12 falling over the last 4 years (to 190 in October 2014), folate was low but just above ref range, VitD back on target, TSH bang in the middle of ref range, all liver functions fine, Ferritin is 275 (way over ref range of 150), Cortisol is very high, no probs with size/ count of RBC, WBC/ eosinophils sometimes higher than normal, which we put down to GF probs and other allergies.

My GP is excellent, someone who listens and is willing to explore other avenues that we can come up with. I want to go back to see him next week but would like to go armed with knowledge! Any ideas on where to go next with this would be greatly appreciated.

Thanks for your time reading this, sorry it's so long!

:) Sarah

17 Replies

Have you had your thyroid tested ? - if so what were the results - with ranges ? :-)


Yes, TSH has been regularly tested and always sits happily mid-range of the reference limits.


Our range here is something like 0.45 to 4.95. Mid-range for me, therefore, would be 2.95. I started going to GP and complaining of symptoms at about 2.6. (Though I didn't get diagnosed and treated until I hit top of range.)

Middle of typical UK TSH reference ranges is very much not a place to sit "happily". Most people who have a happy TSH see it somewhere around 1 to 1.6 - but often lower if taking thyroid hormone.

1 like

Oh. Oh dear. 2.25 to 2.8 over the last few years. Will get him to pull up the results. Thanks for the info Helvella. How did you get diagnosed?


I had a nice set of steadily increasing TSH numbers over quite a long time. So very obviously not a transient "blip". Once I was over range, GP acquiesced. (Some other factors meant he knew he could not ignore me at that point.) By then, I knew at least as much as he did about thyroid.

The number of issues I had was impressive for a mildly hypothyroid person. My FT4 was very nearly at bottom of range by then.


OK so the TSH comes from the Pituitary gland and if the thyroid is happy the TSH should be 2 or below. Mid-range I believe is higher. You really need to know how much T4 the thyroid is producing. This is a storage hormone and does little in the body. Needs to convert into the ACTIVE T3 - so without these two results you will not have a true picture of what is happening in your body....Have you had the thyroid anti-bodies tested ? - Hashimotos is the most common thyroid disorder when all the TFT's can be in range but still the anti-bodies are raised. Without them being tested how would your GP know ?

How are your levels of Iron - Ferritin - Folate -VitD ? All need to be optimal. So many conditions overlap - not least thyroid and B12 deficiency. Chicken or egg ? Are you taking Folic Acid or methylfolate when you have your B12 injection ?. - also a good B complex is required to keep all the B's in balance.

Maybe check out the Thyroid UK website and look at the signs and symptoms and also the forum here on Health Unlocked. You can also check my Profile by clicking onto my name - for the edited version :-)

Happy to help :-)


Helvella - above is an Administrator on Thyroid UK forum - and knows a thing or two..... :-)


Definitely get thyroid tested.

Another possibility is that you have an autoimmune reaction when B12 in serum gets high - as it would be doing with shots - which creates antibodies that try to shut down the mechanism that transports B12 to the cellular level - known as functional deficiency - means high serum B12 but all the signs of deficiency.

This article has an interesting reference to a study in Denmark which showed that 30% of people receiving B12 as a result of deficiency exhibited the response - so it may well be part of the reason why some people - including myself - need to receive a lot more B12 than the text books say

Note: article isn't arguing that high level doses shouldn't be given to people but that high levels of B12 can be indicators of other problems - mentioned in the section on aetiology.

My diagnosis occurred in Dec 2012 following fall that left me hospitalised needing a ankle pinned. I believe I probably had nitrous oxide as an anaesthetic which probably inactivated what little B12 I had left so was in a really bad state when I came out - just couldn't believe how much of an effort everything was - needed to rest every couple of feet. Unfortunately nobody in the hospital went through what symptoms were with me ... and my GP didn't give me any information either - probably because he, like so many others, really doesn't have a grip on the condition - not that it is really one that it is easy to get a grip on as it affects different people in so many different ways.

I was definitely going backwards on the normal regimes for B12 and had got to the point where I could scarcely walk and just didn't know where bits of my body were when I went to see my GP and got the response that it couldn't possibly be B12 because I was being treated. He did one of the standard tests for depression which made me realise, from the reading I'd done, that even someone with B12D who wasn't depressed was going to score high on the test. Having done research and found out that having high B12 isn't toxic I decided that I was going to have to treat myself - ordered some phials from Germany but decided to try really high doses of a nasal spray that I'd been using to keep myself going - and was amazed at the effect - few weeks later I was quite happy perched at the top of a ladder pruning my grape vine - that was about a year ago. A couple of months later I also realised that the anxiety and depression that had dogged me for decades had actually lifted.

I did read one case study on a patient who only recovered when given repeatedly large doses of B12 - which was the way functional deficiency affected him ... and that is probably the only way to go - flood the body with so much B12 that it can't produce enough antibodies to stop the B12 getting through. Suspect this was what I needed to do - I know take around 3-5mg a day - mainly nasal spray but some sub-cutaneous injection - and would supplement even on a day when I have a maintenance shot as the symptoms start to come back within 24 hours.

Being physically active means that you would get through quite a lot of B12 - sounds as if you have some absorption problems - which fits with the coeliacs and vit D - and that also means you have a problem recycling any B12 that you have stored in the liver as that depends on the same mechanism.

You might want to stop the antidepressants - the one you are on is an SSRI and that can affect your folate levels - and as the body needs folate to process B12 it may not be helping, besides which the depression and anxiety are probably the neuropsychiatric effects of the B12D and what you need is to get the levels up high enough for long enough for your body to repair the damage that is causing the short-circuit in your brain that is the mechanism by which depression and anxiety seem to work.

You cannot overdose on B12 - there are no known downsides to having high serum B12 levels so flooding the system shouldn't be a problem.

There is a correlation with larger tumours and higher cancer rates and B12 supplementation but that is probably because cancers started as a result of B12D and, unfortunately B12 is going to also help cancer cells to reproduce - though probably not as much as the extent to which it promotes healthy cell reproduction or the correlation would probably be much more significant. There certainly isn't any evidence - or any biochemistry to support any theory claiming that high B12 causes cancer.

Really hope that you manage to get to the bottom of things quickly. Really good that you have a good GP that is listening and wants to work with you - definitely a keeper :)


Thank you all for your really interesting thoughts. I have always thought thyroid problems but was always convinced by GPs and Endos that I was going down the wrong route. Also considering functional B12d. Such a minefield!


Hello Sassly

I cant have dairy or gluten. Adcal is not good. Read Doctors research on Citrate Magnesium. Read update Magnesium on google. I take Vitamin B12 1000ugs daily & Citrate Magnesium 400mg. We can buy it in the UK but it comes from New Jearsey. I know about all this because our daughter had very bad pain in her legs and her doctor sent her for vitamin & mineral tests and she was low in magnesium

Warm regards and good health


Re TSH, have a look at

TSH is said to be a totally flawed method of testing Thyroid & the NHS keep increasing the Ref range. You don't want to be middle. Thyroid Stimulating Hormone is produced when your cells are crying out for T3.

Have you had your Thyroid properly tested, ie, your Free T3 & T4?

A few things you say point to Hypo Thyroid & that's a real minefield. Please refer to TPAUK to prepare yourself.


Just a thought - SSRI anti-depressants can cause tiredness. I was very very tired on fluoxetine. When I was on seroxat I literally slept all weekend, just waking to eat and then going back to bed. I would go to bed as soon as I got in from work and still not feel refreshed in the morning.

Fluoxetine is meant to be a more stimulating SSRI, but it can still cause sleepiness - and certainly did for me.


Who's your GP? Can we all go to him/her? LOL!! Do you have any idea how lucky you are to have a GP willing to give a jag every 2 weeks?

That being said, you are feeling awful so something clearly still isnt right and it does sound like B12D is still the villain of the piece. If you were so ill when you started on B12 replacement then it sounds as if you had neuro damage and should have had loading doses EVERY OTHER DAY until no further improvements and that can sometimes take months! Thats what I would suggest you push for, providing that all other avenues have been explored and dismissed first.

Gambit 62 has written a reply to you on this that tells you just about everything you need to know.

You've had a pretty rough time of it but I hope you get better soon


One thing nobody mentioned is that when your body is trying to replenish a deficiency you are supposed to do as little activity as possible. I have malabsorbtion disorder with IGA Def. I've been in the hospital how many times over the past few months and

have had many blood transfusions etc. I finally had a good day and decided to mow the lawn. Well within 6 hours I was back in the hospital. Take a break from your training and let your body heal before your commitment to sports does you in permanently. Good luck


Hi Sassy - I'll throw my half-pence worth in, with my first thought being thyroid, but I see plenty of others have already suggested that. Failing that, my next thought would be you are just DOING too much, particularly given your medical history. You don't say how old you are (do you? I have brain fog to rival yours!), but that's a lot to expect of yourself, even if you are a stripling of 21. Lastly, with that pernicious tiredness you keep listing, I have to add in M.E./ chronic fatigue syndrome. Have you had a cold/bug/virus recently? If so you could be looking at M.E, I'm sorry to say. Hope not. X

P.S. I should just add, looking back at your history, if this fatigue started about 2005, your bug or virus could have been caught then. If you can think of a bug that brought you to your knees see if you can correlate the tiredness to it. Anyway, like I say, hope you're not landed with that one...


Really useful info, and I appreciate the time you all took to reply, thank you!

Saw the doc last week, on review (45 minutes appointment, told you he was good!), we decided to go down a neuro route because of the word-finding and balance issues that accompany a 'funny turn'. We discussed Endo too, and if neuro comes back with nothing then that's where we will go next. A good friend of mine is a nutritionalist with Hashi's - she is looking in to getting my TPO done as a first step (for about £50), then can do T3 and T4 later, but they're more expensive.

Potassium: top of range

Folate: top of range

D3: top of range

Latest TSH: 2.5

B12 (but only serum): In the thousands!

Also, as I had a major triathlon this weekend that I'd paid loads of money for, and spent Thur-Mon in bed again, I researched red blood cell formation and along with the info you gave me, bought some B-Complex with B12 Boost sublingual liquid, Potassium, Copper, Magnesium. A nurse friend jabbed me with Hydroxo at 5:30 in the morning before the tri started, and I finished my first half ironman (1.2mile swim, 56 mile bike, 13.1 mile run) in 7:29:26 then drove 4 1/2 hours home, went to bed at midnight and was bright and bubbly from 7am today. Something might be working! I can only hope!

Going to try to keep feeding B12 in sublingually and by weekly injection and see how the story pans out.

Thanks again for you help. :) Sarah


Hey all, especially to Gambit and Shevie,

I've been injecting every 2 days and things are starting to look better :)

I'm self-injecting imported B12, which is a horrid thing to do but I am managing it! As long as I inject every other day and take sublingual liquid on the 'other' day, I seem to be staving off the worst of the symptoms. I even felt the ends of my fingers for the first time in a very long time last week! My imported vials nearly ran out this week so I've been eking things out over more days and hey-ho, lots of symptoms back; crashes, fatigue, pins and needles, numbness, sighs, brain fog, etc, but not as severe as it has been before.

Still got the neuro appt in August, but I'm starting to think functional B12 could be the culprit. Thanks for your support, it's made a huge difference to my health. Please give yourself a hug from me! x :)


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