Intrinsic Factor

[Orchard33]

It occurred to me that it must be possible to synthesise Intrinsic Factor as a supplement to replace what PA people have lost. Does anyone of a scientific bent have any thoughts on this idea?

[helvella]

It seems to be a large and complex glycoprotein.

Synthetic image of intrinsic factor

[palmier]

I think its been tried, or at least with animal intrinsic factor. The problem is, I think, that people with PA have antibodies against the intrinsic factor. B12 is cheap and safe, so it'd probably be more expensive to use "extrinsic" intrinsic factor than b12 even if it worked.

[Orchard33 in reply to palmier]

Many thanks for your reply. I guess any synthesised IF would have to have built in resistance to antibodies. Any thing seems possible these days.

[Technoid in reply to Orchard33]

yes, it has been tried with hog-derived intrinsic factor and although seemed to work initially, after some time absorption stopped, thought to be due to antibodies developing to the "foreign" intrinsic factor. I would be interested to know any tests with human-derived or synthesized intrinsic factor if they existed.

sci-hub.st/https://www.scie...

[Orchard33 in reply to Technoid]

Thanks again for info. Perhaps I'm being overly positive but the idea must have legs as there have been attempts made to use IF from pigs, as you mention, even though that experiment has not so far been successful. A couple of months ago I was intrigued by a mention of developments in the treatment of PA that at the moment are not being made public. I would very much like to know what they might be.

[Technoid in reply to Orchard33]

In the case of AMAG(Autoimmune metaplastic atrophic gastritis), my concern would be that the antibodies might prevent absorption nonetheless because even with intrinsic factor being available, the binding sites are being blocked by the antibodies. Per the NHS site:

"There are two types of intrinsic factor antibody: type 1 binds to the vitamin B12 binding site and type 2 hinders the binding site by binding to structures nearby."

ouh.nhs.uk/immunology/diagn...

[Orchard33 in reply to Technoid]

Thank you, Technoid. I'm very impressed by your sourcing of information.

[tomdickharry in reply to Orchard33]

I've not tried the pig IF but for years needed pancreatic enzymes.Then I developed a severe allergy to them. The NHS does not have a non-porcine option so now I have to take very expensive herbal enzymes. Just saying that any raw animal extract can do that.

[palmier]

B12 has also been synthesised, but it's not easy and much more expensive than using microbs to produce the vitamin.

[Orchard33 in reply to palmier]

Thank you for your reply. I learn something new every day.

[Cobalt1312]

Hi Orchard33, before I realized I had pernicious anemia I was working with a nutritionist because I couldn't stop losing weight. I got a battery of tests done with my GP to try to understand why I was so ill, and she found my B12 was low. I relayed this to my then nutritionist and she recommended a vitamin from Metagenics call IntrinsiB 12 - which has intrinsic factor, methylcobalamin, and methylfolate

I don't know the source of the IF in the vitamin, but initially I felt dramatically better taking it, and then seemed to drop off. I also started to get stinging in my intestines and stomach. I found out later I have pernicious anemia and celiac. The amount of IF in the vitamin is 20 mg, and when my doctor tested my IF antibody serum level it was 19 subjective units. I was taking the vitamin at the time and I think it may have played a part in why I was so highly positive when tested.

My own personal experience with a supplemented intrinsic factor was not one I would repeat. I believe it kicked up my autoimmune issues more.

[Orchard33 in reply to Cobalt1312]

Thank you Cobalt1312. I so appreciate having so much information on this issue. It seems that "foreign" IF can work but not for long and can cause additional problems.

[Cobalt1312 in reply to Orchard33]

I'm grateful you're asking these questions in a place those of us with PA can come together and talk about them. We are stronger together, even if what brings us together makes us individually weaker.

[Technoid in reply to Cobalt1312]

I would be very concerned with any nutritionist who would recommend such a supplement since I'm not aware of any human trials that have tested either the efficacy but more importantly, the safety of providing intrinsic factor in this form.

Of course, its a very interesting idea and sounds promising at first glance but there is not enough safety data for it to be recommended and we do have precedent at least for animal-derived intrinsic factor causing a block in B12 absorption (possibly due to the creation of antibodies to the supplied IF). So I think it was extremely premature for this nutritionist to recommend such a supplement. I think this goes to why it is better to stick with a registered dietician for this kind of advice.

[Cobalt1312 in reply to Technoid]

I agree with you. She is no longer someone I work with, for multiple reasons. Among other things, I think she tried to practice beyond the scope of her expertise. Interestingly, she is a registered dietician. When I said 'nutritionist' I just meant she was helping me with food.

When I told her I'd been diagnosed with PA she responded "Oh don't worry, it's not like it's a disease or anything..." I lost my temper with her. Having a degree doesn't mean you're competent.

[Technoid in reply to Cobalt1312]

"Having a degree doesn't mean you're competent. "

Very true. Sometimes qualifications can help indicate expertise but they certainly dont guarantee it, as you found in your case I see. Very disappointing. I will say, I consulted a registered dietician myself during my treatment but when she expressed extreme concern over my highly elevated B12 levels (I had told her I was on twice weekly injections at that point), I realized I already knew a lot more about B12 than she would be able to tell me about.

[tomdickharry in reply to Technoid]

It's the textbooks they learn from that are the problem.

[Technoid in reply to tomdickharry]

I have a recent standard nutrition textbook here with me:

Understanding Nutrition [Whitney, Rolfes] 2023

and the section on B12 deficiency and toxicity ends with the statement:

"No adverse effects have been reported for excess Vitamin B12, and no UL has been set"

Pretty unambiguous. So I'm not sure textbooks are the issue... maybe its reading comprehension or falling asleep in class 😆

[WIZARD6787 in reply to Cobalt1312]

"Having a degree doesn't mean you're competent."

Obtaining a degree and a licence to practice any profession means you are qualified and can receive payment for your time. It is not an indication of competence.

Physicians and other professionals have a tendency to believe that their training makes them competent in all areas. They tend to believe that life and all professions are simply a matter of being trained by the current multiple testing.

As a private environmental consultant I will not work for a dentist or physician as they have the belief that my work is a matter of following a check list as theirs is. It just takes longer to deal with them and not profitable. They keep telling me how to do my work.

Ironically lawyers are great to work with as they don't think they can do my work. Well some of them anyway.

I often wonder if a Physicians emotional maturity is based on the age when they decided to be a physician.

[wedgewood]

I also tried a supplement with porcine Intrinsic Factor , years ago . No effect at all ! Logical really as someone pointed out , as I have P.A. proven by having a positive test for Intrinsic Factor Antibodies! How stupid I was not to have thought that through !

[Orchard33 in reply to wedgewood]

I had no idea such a thing was available. I wouldn't consider it. It's very clear that it doesn't work. Thanks for sharing your experience.

[Stmargsgirl]

I think you can buy intrinsic factor tablets online but they haven’t been clinically tested as far as I know.

[Orchard33 in reply to Stmargsgirl]

Not a good idea, then.

[Orchard33 in reply to Orchard33]

Many thanks for this interesting and informative discussion.