I have high RT3 & a low FT3/RT3 ratio. A healthy ratio is 20 & mine is 9.09--bad. Recently had a complete iron panel & ferritin is fine. All my doctor would do was serum cortisol, which doesn't reveal much. I'm going to pay for my own cortisol DHEA saliva test. It's not expensive to send off to a lab. It measures cortisol by testing four times during the day. It's not the total or average that counts, but if cortisol levels are normal at specific times. For example, if cortisol is high at night people have trouble sleeping. If it's low in the middle of the day, people lack energy. If it's really high, it means adrenals are ready to poop out & become deficient. Thyroid & adrenals are inter-related. You can do something about cortisol by supplementing. From what I've read, cortisol is treated for a relatively short time to get adrenals balanced. Not lifelong like thyroid.
I need to research thyroid supplementation & osteo risk. I'm guessing that research was done just on levothyroxine & not with subjects using natural dessicated thyroid or those on only T3 or a combo of T3 & natural. Calcium supplements interfere with thyroid supplement uptake.