What supplements should not be taken with thyroid medication? “You should also avoid any drugs or supplements that contain iron, calcium, or magnesium for at least four hours after taking your thyroid medications,” says Dr. Jaiswal. That also includes multivitamins that contain these minerals.
Can biotin damage your thyroid? Biotin is a common component of multivitamin preparations and at high doses it has been reported to cause interference in immunoassays resulting in abnormal thyroid function tests .