Alot of times insurance will require you to get a referral to an endocrinologist(or any specialist) from your GP in order to cover the appointment(s).
A word of warning though:
being on the MRC diet (or any diet, really) will result in innaccurate test results, and therefore a waste of money/wrong diagnosis/treatment. You should be off any diet for at least 2 weeks before having any work done that involves thyroid, reproductive and other hormone levels. Caloric deficits, and especially ones involving low carb intake will alter your *normal* levels
"All the Secrets of your foundation shall come to light.... and when you lie, uprooted and broken in the sun, then shall your lies also be separated from your truths" Nietzche
"I do not workout. I TRAIN.
I do not eat. I FEED.
I do not sleep. I RECHARGE.
My greatest fear in this life is the fear of being ordinary
1/2 Marathon - 1:50:48
5 miles - 36:12