B12 Testing

[Pain12345]

My GP tested my B12 in late June and it was 248. She gave me a B12 (Cyanocobalamin) injection on June 30th without doing any other tests. I then went to see a neurologist and she couldn’t believe that the GP had not done more testing. The neurologist has me scheduled today for the following tests: B12, Folic Acid, Homocysteine Plasma, Methylmalonic Acid, Gastric Parietal Cell Antibody, Intrinsic Factor Antibodity, and Vitamin D.

Do you think that any of the additional tests will be impacted by the B12 injection which I got 3 weeks ago…should I wait another week or so before getting the tests?

[Nackapan]

Firstly I would applaud your gp for giving b12 so quickly. Also getting g to see a neurologist who knew about these blood tests and ordered them.

Depending on the range it also not low so I'm guessing good again going on Symptoms.

A long as the latest lab equipment used the IFA test shoukd not be affected

Thete is a possibility of a false positive if b12 levels still high .

So the bigger the gap i guess better.

Do bear in mind even if negative PA is stil possible.

It picks up 40-50% of thoses with PA.

The other tests adding to your picture.

If b12 done it shoukd be high still

Not sure why only one b12 inje tion?

In the UK a loading doses is given. 6 over 2 weeks.

[Pain12345 in reply to Nackapan]

Thanks. The GP said 1 injection a month- no loading. The neurologist disagreed- said she believed in being aggressive- daily for a week, then weekly for 4 weeks, then monthly.

[Nackapan in reply to Pain12345]

Perhaps the neurologist wil recommend his / her regime once yiuve had yiur bloods done

[Gambit62 Administrator]

serum B12 probably will be affected by the injection and you may well come back with a very high result. Homocysteine and MMA also likely to be affected by injection - folic acid, GPCA, IFAB and vitamin D won't be. WHO doesn't recommend use of GPCA anymore because of high rate of false positives. However, if they insist on doing all of the tests then waiting an extra week is unlikely to have a significant impact on the results.If you have neurological sysmptoms from the deficiency then you really do need an aggressive loading regime as recommended by neurologist.

[Pain12345 in reply to Gambit62]

Thanks. I got the blood drawn by the GP a couple of hours ago. The neurologist told me to start the loading doses - not to wait for the results. Starting those tonight daily for one week, then weekly for 4 weeks, and then monthly.

[Gen89]

I can’t answer the question about the waiting for tests but I am very impressed by your neurologist.