There has been discussions in this group about Biotin, hair loss and effect on thyroid lab tests. I have ignored because I do not take a Biotin supplement. I just realized that that my Multivitamin contains Biotin.
So, if you’re taking a multivitamin and are being tested for thyroid levels, be aware that it may affect the result of lab results. There is a simple solution, if your multivitamin contains Biotin, stop taking for few days prior to blood work.