Hello @lbishop, Welcome to Connect. Here's some information that explains the connection between the thyroid and Vitamin B6 that might be helpful.

"Does vitamin B6 affect thyroid?
Without this vitamin, the thyroid cannot utilise its iodine raw material efficiently to make the hormones. Pyridoxine B6 is needed even more by an overactive thyroid. Muscle weakness is very common in people with an overactive thyroid and in those who are also lacking in B6."
--- Vitamins and minerals and their importance for the Thyroid: https://thyroiduk.org/role-of-vitamins-and-minerals/.

You mentioned that you have been avoiding any supplements and trying to eat a low B6 diet. Do you drink any of the popular sports energy drinks which can be high in B6?