B12 & raising levels?

[Minimouse1]

If riaising B12 levels by sublingual supplementing, how do we know we have achieved a decent level - is it judging by symptoms alone? Im thinking any re-test of levels would give a false impression whilst on supplements?

[Bearo]

If you supplement for about three months then stop your supplements a week before the blood test it should show your own level. But I’m very new to this site and only going by what I’ve read here, so hopefully Seaside Susie will confirm or correct.