A query about blood testing.

[Golli]

I’m a member of thyroid uk site and have since gravitated to this site due their good advice .This is my first time posting here.

I’m due my annual blood test at the end of September. At present I’m taking Igennus Super B-Complex x2 daily (with900 ug methylcobalamine)

I know to stop these a week before test due to the biotin skewing the results, But I’m wondering if my levels will give a false reading due to taking the supplement?

Since taking B12 my levels have been slowly increasing , some results……

6/4/20

Vit B12 active. 52.1. (37.5-187.5)

3/11/20

Vit B12active. 64.4. (>37.5)

10/5/21

Vit B12 active. 75 (>37.5)

I did have some neurological symptoms since last year which have improved since taking the supplements and going gluten free , which has improved absorption. , but I’ve never been tested for Pernicious Anaemia. Would I need to stay off the Vit B complex ( which I’m reluctant to do) , for a long time before being tested for PA , in order to have an accurate result?

Thank you for in advance . I would be very grateful for any advice.

[Gambit62 Administrator]

if you mean testing for IFAB (the test for PA as a cause of a B12 deficiency) you would have to stop taking the supplement for about 2 weeks before the test because of the risk of a false positive. There are different test methods and some only require 48 hours but to be on the safe side I'd suggest 2 weeks. However, you should also bear in mind that the test isn't very sensitive and gives false negatives 40-60% of the time (exact %-age depends on the test method).

If you have found that the supplement is working then I would stick with the supplement.

[Golli in reply to Gambit62]

Thank you so much for your response, it’s very helpful.