IFA test after B12 shots

[Cinders70]

My GP told me today that she won’t re-test my blood for IFA as once I’ve started B12 shots it gives false positives.

I’m aware that the IFA test often gives false negatives.

Is she correct?

I’ve been told to increase my antidepressants.

[Gambit62 Administrator]

It does give false positives but only if it is done very close to an injection - the most recent test methods only need 24-48 hours for the risks of false positives to reduce - but it's best to leave it 2 weeks which is the time taken for less recent test methods - because you don't know in advance what test method the lab is going to use - unless they clarify beforehand

[Cinders70 in reply to Gambit62]

Thanks Gambit62