Blood Tests: Hi Could someone let me know when... - Thyroid UK

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Blood Tests

Hi

Could someone let me know when you stop taking iron supplements before an iron blood test and ditto for B12?

Also are there any other supplements that should be stopped prior to a blood test?

Thank you.

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mischa

Iron - stop 7 days before test. Do the test early morning after an 8-12 hour fast, you can drink water.

B12 - do you want a baseline or do you want to know if the dose you are taking is appropriate? If you want a baseline to see what you are holding on to then you stop B12 4-5 months before testing. Otherwise Medichecks suggest leaving it off for a week.

Other supplements - Biotin or a B complex containing Biotin you leave off for a week. Anything else you don't need to stop but don't take until after the blood draw on the day of the test.

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Oh that's useful. I do want a baseline so I'll continue with the B12.

Yes, I almost forgot about the Biotin - I'll leave off the B complex.

Thank you for your quick response.

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Oh that's useful. I do want a baseline so I'll continue with the B12.

As mentioned above, if you want a baseline result then you discontinue B12 for 4-5 months.

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Sorry, I didn't read it correctly and I was rushing to go out. No I don't want a baseline - merely my levels as is minus the week.

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