High dose sublingual B12 supplementation and the Intrinsic Factor Antibodies test.

[longdistanceclaraDXB]

Diagnosed with a b12 defiency just over a month ago. Went vegan end of January and I think doc just assumes thats the reason as he doesn't really seem interested in any follow ups or reasons.

I've been reading like crazy and actually think I've been deficient for most of my life and have also just found out my gran was diagnosed with PA too.

So I am busy prepping myself for my next doctors visit where I intend to ask for the Intrinsic factor antibodies test, the Parietal cell antibodies test and a serum folate test as none of this was mentioned to me at all previously.

My worry is thought that I've been supplementing B12 with high strength (5000mcg) sublingual lozenges and have just read this on the PAS website - "You should not take any supplement before having your B12 assessed and/or having the test to find out if you have the Intrinsic Factor Antibody." Is this going to make the test completely pointless for me? Can I stop supplementing now and wait a month or so maybe and get a more reliable (yes I know its a flawed test anyway) result?

I am purposely not supplementing folate yet as don't want to skew any results there but not sure what I should do now about the IF test.

What to do?

TIA

[fbirder]

The answer is - it depends.

Back in the 1980s the anti-IF test could easily be upset by high B12 levels and people were advised to stop supplementing for several weeks. At the end of the 1980s a new test was developed that wasn't so sensitive and the break in supplements was shortened.

About 10 years ago a new test was introduced that suffers no interference from B12.

So it all depends on which test they use. Unfortunately you won't know and it's highly unlikely that your doc will know. It's very unlikely that the test will be the 35 year-old one, but I would guess it's possible that it's the 25 year-old test.

Personally, I would leave it a week and cross my fingers.

[wedgewood]

When I was diagnosed with P A 18 months ago, I was covered with B12 patches and had been taking sub-lingual B 12 lozenges , about 5 a day , for at least a fortnight . My b12 was sky high . Inspite of this , the antibodies to Intrinsic Factor were revealed .

So the high B12 serum level had no bearing at all on the IF test .

But as we know ,absence of IF antibodies doesn't prove that P A is not present.