Pernicious Anaemia Society
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B12 dangerous???

Took my Autistic daughter with Pernicious Anemia to a NEW doctor yesterday. We live in the USA. The doctor is a specialist in Gastroenterology and immunology. She spent two hours with us and listened to our story. When I told her that we did loading doses for 7days she was shocked! She said the primary doctor was doing something very experimental and it could be dangerous?? Can't tell you exactly what her reasoning was but something about if other levels are off and you are putting too much B12?? I did get alittle nervous😆 She did get us an appt with a genetics specialist and she is doing a endoscopy and colonoscopy in April.

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She might have the information a bit backwards in her mind. A person does need to have good levels of folate, iron, and potassium when getting B12 so that everything works together optimally. And it is possible to become dangerously low in potassium when high doses of B12 are administered. But plenty of foods are potassium rich and as long as her levels are being monitored it really isn't a problem. The part that your doctor might have gotten backwards involves folate.

There is a recommendation that, if a patient shows indicators for megaloblastic anemia, doctors should not immediately supplement folate because the deficiency may be B12. Giving folate to a patient who is really B12 deficient may appear to correct the anemia but it won't stop neurological damage that is caused by B12 deficiency. However, if a patient is deficient in both folate and B12, it is ok to supplement both at the same time.

I'm in the US also and I have not found there to be any sort of generally accepted practice involving loading doses here. It seems like most of the doctors I've encountered have been out of their depth on the subject of B12 injections. At this point, I tend to simply expect that I will have to educate any new doctors I encounter on the topic. You will probably have to do that also.



I'm in UK.

Have you read the book "Could It Be B12? - An Epidemic of Misdiagnoses" by Sally Pacholok and JJ. Stuart? The authors are american.

It has a chapter that mentions possible connections between b12 deficiency and autism.

There is also a paediatric version of the book "Could It Be B12? Pediatric Edition: What Every Parent Needs to Know"

B12 Awareness website (USA website)

PAS (Pernicious Anaemia Society)

PAS is based in UK but has members from around the world ranging in age from toddlers to 80 plus.


PAS tel no +44 (0)1656 769 717

Martyn Hooper, the chair of the PAS has published several books about PA and B12 deficiency. His latest is "What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency"

There are 2 PAS support groups in USA.



Also in the Pacholok book, on page 223 it discusses the old treatment protocol for treatment of B 12, which does include seven daily loading doses, followed by weekly injections for four weeks, followed by monthly injections. This is how my doctor in Massachusetts treated me when I was first diagnosed. I think this is actually a well established treatment protocol in the US. There are suggestions that this should be changed, which are discussed in the same chapter, but I think many doctors still follow this plan.


Thank you for the info! Made me feel better that you also did loading doses. I will definitely invest in the book. This has been a very long ordeal for my daughter and it is hard with her limited communication. If you don't mind me asking, do you feel well getting one shot a month? And what were your symptoms?

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The book is an excellent investment. One shot a month for me does not seem to be enough. When I was doing them more frequently, I definitely felt better. I just saw my doctor today and we discussed it. She had actually asked me to do a trial of 2000 mcg oral B12/day, and I was miserable. My main symptom is muscle twitches throughout my body, mostly in my legs. They aren't painful, but I feel that if I was getting enough B12, they might improve. I also had fatigue, general achiness and foggy thinking, but thought it was just my age. I'm advocating for injections every week or every 2 weeks. I have learned to self inject, so it's really just a matter of cost and whether or not the insurance will cover more frequent injections. My doctor was open to whatever I feel works, so she gave me an injection today and I left her with a bunch of articles to read, and we will reconnect after I see the neurologist in 10 days. I think the best thing you can do is learn as much as you can. My doctor was very willing to say there is a lot she doesn't know, and she is willing to learn and open to info, but I know that's not always the case. If you plan to advocate for your daughter, it is best to learn as much as possible so you can make a good argument. If you haven't found them already, the pinned posts on the right of the home page for this forum are an excellent start, and then as you read, you may find other resources and articles. Good luck!


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