Do I have to stop biotin supplements before taking my test?

We recommend that all vitamins and minerals are stopped at least 24 hours before taking your test. There are two exceptions to this.

These are:

• Biotin: You’ll need to stop biotin supplements at least 2 days before taking your test. Biotin can interfere with the test process at the laboratory and can lead to inaccurate results. Please speak to your prescribing doctor before stopping biotin supplements if these are prescribed.
• B12: If you take a vitamin B12 supplement or injection, we recommend that you stop taking this 2 weeks before your test. This means you can get a true reading of your active B12 levels outside of your treatment. If these supplements are prescribed, please speak to your prescribing doctor before stopping any medication.