My 16 year old son had been experiencing dizziness, headaches, low energy and tiredness for the last year. He was sent for blood tests where it was found his b12 level was 135. He was immediately sent for an intrinsic factor antibody test and afterwards began the loading dose of b12. We just found out the antibody test was negative.
I was wondering if anyone had any advice or information for us regarding what we should be expecting/asking for from the doctor. There seems to be so little information regarding juvenile b12 deficiency/pernicious anaemia. The doctor told us it was rare for a teenager who isn’t vegan to have deficiency.
Thanks in advance for your help.
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Redazzy
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It is known that a negative Intrinsic Factor Antibody test is about 50 % inaccurate . In the absence of other reasons for a low B12 reading , treatment should be started for the symptoms .
IFAB test isn't very sensitive - around 50% of negatives are false negatives.
IFAB test is specific which means that it rarely gives a false positive.
So, if the answer is positive then its almost certain that you do have PA but a negative is a long way from ruling out PA as the cause of B12 absorption problems
This webpage from the pinned posts on the right (or below if you're using a phone) has some useful info. B12 values are all in pmol/L. To convert to ng/L multiply by 1.355.
I have been posting recently as my 17 year old daughter has recently had a blood test, as we suspected she was anaemic. Her ferrratin level was just in range, but her b12 was 95, so very low. She has had loading doses back in October and is currently back on every other day injections due to neuro symptoms- tinnitus, numbness and strange sensations in her throat making her eating difficult. We have been back and forth to the GP who is listening, and very sympathetic, but not very well up on b12 deficiency. Her intrinsic factor also came back negative- not vegetarian or vegan. It’s been such a difficult time - 6 months ago she was the picture of health.
I really hope you get the support you need for your son - how is he coping with it? this site has been amazing source of information- I now feel I have to prepare myself for battle every time we see the GP as he is keen to stop injections as soon as possible. She is much much improved on every other day b12 and it feels like we almost have our daughter back. I do feel fearful for her though - having to manage this from such a young age feels overwhelming at times.
Good luck. I keep trying to find an expert/consultant- there doesn’t seem to be one !
Read through this for more information, especially on how the IFAB test is wrong 50% of the time, how symptoms are the most important factor, and how further blood testing is pointless once injections have started - onlinelibrary.wiley.com/doi...
If you join the PAS then you can download their information leaflet about PA in juveniles. pernicious-anaemia-society....
I was finally diagnosed with PA at 20yrs old after being a sickly child and teenager.
Age 64 now I wish I had known more about it. You’ve got to read lots and find a good GP who is willing to listen.
I really needed more regular jabs through the past yrs but just thought they knew best unfortunately they don’t. Keep in control of your own health.
Struggled with hypothyroidism without knowing what it was that was affecting me. When I went back to haematologist check, they said they had been waiting for me to return with further problems. Great!!!
Keep an eye on your thyroid before you become too unwell again.
Overdosed with thyroxine for 30 yrs as GP approved all tests which were wrong!!
Hopefully there will be more awareness in your lifetime and you can enjoy good health. It’s been ignored for too many years.
Trying to get my mum tested at 87 yrs old now. A struggle to get the active B12 test
She’s been scanned screened xrayed and nothing found. Mentioned PA still ignoring me.
Guidelines link below suggests anyone with unexplained B12, folate or iron deficiency should be tested for Coeliac.
UK GPs sometimes forget to ...
a) Do both the following tests
tTG IgA test
Total IgA test
Perhaps you or your son can check both of these were done?
b) tell patients to eat plenty of gluten in more than one meal per day for several weeks before blood is taken
If GP didn't do both tests and didn't ask him to eat plenty of gluten for weeks before tests then the results may not be reliable. See links below for more info.
Nitrous oxide is sometimes used as a recreational drug.
4) Any chance of internal parasites eg fish tapeworm? Does he ever eat raw or uncooked fish eg sushi/smoked salmon etc? There are other parasites that are associated with B12 deficiency eg other types of tapeworm, plus Giardia Lamblia and others.
5) Any family history of conditions that can affect the gut eg PA, Coeliac, Crohn's disease, Diverticulitis etc
6) Diet
Was he asked questions about his diet?
Does he eat plenty of B12 rich food eg meat, fish, shellfish, dairy, eggs, foods fortified with B12?
If yes then diet is less likely to be cause of b12 deficiency and it's more likely to be due to an absorption problem in the gut eg PA, Coeliac etc.
A vegan or vegetarian diet can be a risk factor for developing B12 deficiency.
May be worth writing out a typical weekly diet, food and drink, so GP can see typical diet.
Excessive alcohol consumption can affect B12 levels.
7) Some medications can be associated with B12 deficiency eg metformin, a diabetes drug, PPI drugs eg omeprazole and there are others.
Any concerns about medication should always be discussed with GP.
Link about "What to do next" if B12 deficiency suspected
All the books below mention young people with B12 deficiency. Some of the case histories can be upsetting to read.
"What You Need to Know About Pernicious Anaemia and B12 Deficiency" by Martyn Hooper
Martyn Hooper is the chair of PAS (Pernicious Anaemia Society). Book does not show updated BNF info.
"Living with Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper
Has several case studies.
"Could it Be B12?: An Epidemic of Misdiagnoses" by Sally Pacholok and JJ. Stuart (USA authors)
Very comprehensive with lots of case studies. There is also a paediatric version of this book "Could It Be B12? Paediatric Edition: What Every Parent Needs to Know".
I also plan to read "Vitamin B12 deficiency in Clinical Practice" (subtitle "Doctor, you gave me my life back!" by Dr Joseph Alexander "Chandy" Kayyalackakom and Hugo Minney PhD
How many B12 loading injections did he or will he have and how often will he get maintenance jabs?
1) UK recommended treatment pattern for B12 deficiency without neuro symptoms is ...
6 B12 loading jabs over 2 weeks followed by a jab every 2 or 3 months
2) UK recommended treatment pattern for B12 deficiency WITH neuro symptoms is ...
A B12 loading jab every other day for as long as symptoms continue to get better then a jab every 2 months
There is no set time limit for how long every other day loading jabs can continue for those with neuro symptoms.
BSH link suggests possibility of a review of loading injections after 3 weeks of every other day loading jabs for those with neuro symptoms but my understanding is that if symptoms are still improving at 3 week mark then the every other day loading injections should continue.
I'm assuming he has been put on an adult treatment pattern as he is 16. If he is being treated as a child then the pattern may vary a bit. See link below.
If he has any neuro symptoms then my understanding of the guidelines (I'm not medically trained) is that he should be on the second treatment pattern whether treated as a child or adult.
Neuro symptoms associated with b12 deficiency can include ....
tingling, numbness, pins and needles, burning sensations, insect crawling sensation, tinnitus, muscle twitches, muscle fasciculations, flickering eyelids, restless legs syndrome RLS, vertigo, migraine, clumsiness, dropping things, bumping into things, strange gait (unusual way of walking), word finding problems, forgetfulness, balance issues, brainfog, proprioception problems (problems with awareness of body in space), strange behaviour eg car keys in the fridge etc?
Check lists below for other possible neuro symptoms
In relation to B12 deficiency, GPs often look for signs of peripheral neuropathy (PN) especially signs of sensory neuropathy so worth mentioning signs of PN.
Does his GP have a list of all his symptoms especially every neuro symptom?
Dietary B12 deficiency is sometimes treated with low dose cyanocobalamin tablets. My understanding is that severe dietary deficiency eg where there are neuro symptoms, should be treated with B12 injections.
It's vital to get recommended level of treatment or there is a may be a risk of neurological damage.
Symptoms Diary
Some on forum find it helpful to keep a daily symptoms diary which tracks changes in symptoms over time and when treatment is received. It can be useful evidence of improvement or deterioration in symptoms.
I wrote a very detailed reply on another forum thread which may have some info I've not included in this post.
1) B12 deficiency is not always well understood by GPs and specialist doctors so it pays to be well prepared for any appointments.
2) Some GPs are not able to cope well with assertive patients so be prepared for GP/patient relationship becoming strained and have a back up plan eg another GP surgery to go to.
4) Some areas of UK have guidelines on treatment/diagnosis of b12 deficiency that are out of date. I suggest you track down the local guidelines for your area and compare them with BSH, BNF links in this post and links below.
There are many different areas that the “processing “ of B12 can breakdown. I have a child that is 17 and I’m in the process of getting him diagnosed. Most doctors are not aware of other causes beside PA. At least in your son’s case the B12 reading was low enough to prompt treatment, there are others, “disorders of intracellular cobalamin and remethylation disorders” where the B12 in serum is in the normal range but the body can not use it because it is not metabolized properly. Also there is a genetic condition called Imerslundgrasbeck syndrome where there is a defect in intrinsic factor. I also just found out that biotinidase deficiency (a different B vitamin and which may be the case for my child) causes a difficiency in B12.
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Intrinsic antibody test after B12 multivits
B12 and folate deficient but negative intrinsic factor. 
Intrinsic factor
Intrinsic factor antibody test ranges?? 
