I went to the doctors yesterday and my B12 was tested to be 1457 (my blood was taken the week before when I was taking sublingual B12 everyday, and I had taken it the morning of the test). What do you think of that result?

Also, I am going to be tested for intrinsic factor and pernicious anemia. I'm not taking B12 sublingually anymore (at least not until I can get some methylcobalin tablets), but should I stop taking my iron tablets before the test? Is there anything I need to do or not do so that the test is accurate?

Thank you!

If you were taking B12 when you had the test, it would show
an elevation.

It is best to stop B12 1 week before the test.

The Schilling test I believe was discontinued, several years ago in most labs in US.

Today they do antibody tests for damage to parietal cells of the stomach.

To see if your cyano is "working" and not just floating around in the blood, a MMA test and/or homocysteine would be useful.

B12 lowers MMA, and if MMA is elevated, that indicates that the B12 is not working.

The iron would show up on some tests in the CBC perhaps.

It is always best to stop taking supplements before blood work is done.

One value that becomes elevated in the CBC and is a warning marker of low B12 is the MCV...mean corpuscular volume. This measures if the red cells are too big, which happens when they are poorly formed due to low B12 levels. Sometimes the MCV
is elevated before other tests show positive.

Mrs D, I have seen a naturopath and she took a fingerprick of my blood and put it under a microscope and showed me on a screen - I could see that there are a few blood cells that are bigger than normal. Does that mean I have PA?

I live in Australia so I'm not sure whether we do the Schilling test here. My Dr ordered it, so maybe they do it here. How is PA tested? Are low B12 and PA mutually exclusive or are they usually diagnosed together?

Pernicious anemia causes low B12.