Thyroid UK
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Vitamin B12 test


I am planning to go to St Thomas's for the Vitamin B12 test in a week's time, the one that is recommended on Thyroid UK.

Two questions:

Should I be having the test at a particular time of day, on an empty stomach etc?

Should I stop taking my Vitamin B complex now? It's very much an average one and as I look on the bottle I see it contains 100ug of cyancobalamin.



2 Replies

Halinka, stop supplementing now. If you want a baseline result you need to leave 3 or 4 months between supplementing and testing. I'm not aware B12 needs to be a fasting test and I think any time of day is fine.


Thanks Clutter. I am hoping that if there is indeed a deficiency, the non-methyl B12 I have been supplementing with will not have touched the sides, and something will still show.


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