I'm aware that a low liver glycogen level inhibits T4 to T3 conversion and therefore may lead to symptoms of hypothyroidism.
But is there a connection between the level of ketones in the blood and thyroid function?
Suppose somebody eats a moderate carb diet of say 50-100g carbohydrates per day, if he begins to include large amounts of coconut oil (medium chain fatty acids), the liver will start to convert them to ketone bodies. Now my question is: Despite not being depleted of liver glycogen, will the raised ketone body level signal the thyroid to reduce it's function?
"Despite not being depleted of liver glycogen,"
50-100g is pretty low, and ketones do not refill liver glycogen. So you may be pretty close to depleted if you're active.
edit: I don't believe that ketones themselves cause the lowered thyroid function, but rather the metabolic stress that leads to ketone production (elevated catecholamines) may also be responsible for lowering thyroid function.
If you are not glycogen depleted, eating coconut oil is not likely put you into ketosis. I know it can, but I think you'd also have to be avoiding glucogenic amino acids.