“…I've seen two people over the last 40 years for whom that was too much, their heart raced and they had to go back to even 15 micrograms for these oversensitive people can make their heart hurt or go too fast. They have to supplement both sugar and magnesium. The thyroid lets your cells retain magnesium and potassium, and so eating well and maybe supplementing magnesium helps you adjust to the thyroid because your muscles will take away the necessary magnesium and cause your heart vessels to constrict and cause heart pain. I hope you don't.”