Thank you for the question.
It is generally safe to take vitamin supplements if you have thyroid disease, including vitamin A.
For the treatment of acne, a vitamin A analogue, isotretinoin is often prescribed. This is indicated for individuals with moderate to severe acne.
It is generally safe to take isotretinoin in individuals with thyroid problems. There are however rare reports on the association of isotretinoin with thyroid disease like autoimmune thyroiditis, although a definite link has not been conclusively established.
Do let your prescribing doctor or dermatologist know of your concerns about thyroid disease so that they can advise you further on this.