Intrinsic Factor (IF) Antibodies testing while on B12

[Treesong2023]

Hello folks - If someone has IF Antibodies and is taking b12 ...would that affect an IF and IF Antibodies blood test..? I dont think it should - as if you have errosive gastritis / malabsorbtion issues etc, you got them...and the B12 wont improve that in any way...?

Thanks lovely PA folks

Xx

[Gambit62 Administrator]

Taking the IF test too close to an injection can cause a false positive - the time interval depends on the exact methodology/kit used - could be a week but more modern kit would be 48 hours.

[Treesong2023 in reply to Gambit62]

Thank u Gambit62. So, I refer to a IF antibodies test here - just checking. If so, i would need to be off the B12 for 7 days I reckon.

[Gambit62 Administrator in reply to Treesong2023]

The IF test is so prone to false negatives I'm not entirely sure it is worth doing but a week - possibly 2 to be on the safe side - haven't double checked but think it might be 10 days for older equipment

[Treesong2023 in reply to Gambit62]

Thank yoo !

[jimmel196]

I'm in the US and LabCorp website says to be off b12 supplements 2 weeks before IFAB testing. I did speak with the Director of their immunoassay dept. who told me that the current testing assay they use is not affected by b12 levels. I guess it would depend on the lab but to be safe 2 weeks off b12 supplements should be sufficient, this is only my opinion.

[Treesong2023 in reply to jimmel196]

Thank for you information Jimmel. Kind Regards from the UK.