Taking the right supplements has the potential to dramatically improve your thyroid and either help it work better or prevent future problems from occurring. Whether you're trying to optimize your thyroid function because you have an existing problem like hypothyroidism or because you just want to prevent a future thyroid problem from occurring, these are, in my opinion, the 5 best supplements to take for your thyroid EVERY day: 1. A daily multivitamin. A multivitamin because your thyroid is inc