I have a very strong belief that a better understanding of how these hormones work in our bodies, how our bodies use them, etc. is a key point in understanding what we have to do, as residents in these new bodies, to make them as healthy and functional and fun to live in as we possibly can.
In that light I have tried to simplify a very important aspect of how this hormone stuff works, specifically thyroid hormone conversion......
aka Topper (Linda)
First we need to take into consideration that....
The body runs through, well.... an inventory/census, lets say...
It monitors how much hormone is in the blood stream
How many receptors are empty and what needs filling...
What processing and system functions (digestion, metabolism, energy levels, body temp all that happy stuff) are doing...
It keeps track of how much hormone is becoming available, and how consistently, either through gland production or supplementation
Once the body determines how much more of the T4 can be taken from the blood it is removed from the blood stream and stored in the cells, attached to hormone receptors, that is where it sits and waits to be converted..
It will never strip all the T4 out of the blood, cuz if it did none would ever get to the nether regions of the body, so some parts of our insides would work significantly better than other parts
This is actually why I think our symptoms vary so much... it may have to do with how the saturation levels and distribution of hormone through the cells and receptors varies leaving some things working better than others... and that saturation/distribution variation being what causes us to experience different symptoms--- that's just an idea of mine.. I don't have any real proof....
So your body is doing all this figuring... if there is this much hormone available consistently then I can use this much of it for stashing away, if the level stays consistent and I can keep stashing away at this level for a long enough period of time to make it worth the effort of doing a 'throttle' adjustment on conversion..... then it's a go.
Once the body reaches the stage where it feels that supplies of hormone (again, be it from the gland or what we take as a 'med) is consistent.. then it kicks up how much of that stored T4 can be converted into T3.
The 'scientific' numbers that they use say that 80% of the T4 that we have available in storage is converted to T3, and must then be replaced. Again, our bodies never strip out the last of it.... it is stored there to cover for the 'lean times' when, for whatever reason, the input of hormone is interrupted it will always have something to draw from until the gland can catch up.... to keep the basic body functions going, to keep us alive.
Does that make sense? Are you with me so far?
The conversion process requires several things to take place
All these things must be available for this chemical process to take place, if any of the parts are missing conversion can be greatly impacted, even stopped completely.
Enough T4 stored in the cells to allow there to be enough 'raw material' to do the conversion process in the first place.
Sufficient AND consistent levels of energy (blood sugar) in the blood to allow the chemical process to take place. (this is the reason for the harping on NEVER skipping meals and trying to eat at least every four hours (mini meals)... if energy levels drop from not eating... conversion stops. No conversion, no T3... T3 is the major active thyroid hormone and without it we are hypo.)
Sufficient levels of Selenium in the blood. Selenium is used during the chemical process of conversion... The Selenium attaches itself to one of the four iodine molecules on a T4 molecule and pulls it off... turning it into a T3, now it can be used to make our body organs and processes work.
So... not enough T4 stored, insufficient conversion of active hormone.
Inconsistent dosing of meds.... throws off the 'census' and delays increase of conversion
Skipping meals, or dropping caloric intake down too far halts or slows conversion.
Insufficient selenium levels slows conversion...
It's up to us to make sure that all these things are covered, so that our bodies can do all the things that they have to do for us every day.
With everything we do to help our bodies work better, and make up for our poor (or non existent) thyroid function....
the MOST IMPORTANT thing we have to work on is getting our Free T3 levels up to the level needed for our bodies to be able to function in a healthy manner
We have two ways of doing this when our glands are no longer functioning correctly.
1) By doing everything we can to support our body's ability to convert thyroid hormone.. including sufficient replacement dosage, proper eating habits and correct supplements
2) By adding T3 hormone to our regimen either through the use of a natural thyroid product, like Armour Thyroid (or it's generics) or by adding a synthetic T3, like Cytomel (or it's generics).