Does biotin affect underactive thyroid? Most commonly, biotin use can result in falsely high levels of T4 and T3 and falsely low levels of TSH, leading to either a wrong diagnosis of hyperthyroidism or that the thyroid hormone dose is too high.
What supplements should I avoid with hypothyroidism? According to the Mayo Clinic, supplements such as calcium, iron, multivitamins containing iron, and antacids containing magnesium or aluminum can potentially have interactions with thyroid medications. They should be taken several hours before or after your thyroid medication to avoid an interaction.