COMPENDIUM ON FUNCTIONAL MEDICINE - Flipbook - Page 159
● Enhances thyroid hormone synthesis
● Promotes growth and development of thyroid follicular cells
● Stimulates iodine uptake by the thyroid gland
Thyroid Hormones (T4 and T3)
The thyroid gland primarily produces two hormones: thyroxine (T4)
and triiodothyronine (T3). T4 constitutes approximately 90% of
thyroid output, while T3 accounts for roughly 10% [4]. These
hormones are synthesized from tyrosine and iodine within the
thyroid follicular cells and stored within thyroglobulin until release
into circulation.
Once released, thyroid hormones are predominantly bound to
transport proteins in the bloodstream, primarily:
● Thyroxine-binding globulin (TBG) 3 binds about 70% of
circulating thyroid hormones
● Albumin 3 binds approximately 15-20%
● Transthyretin (pre-albumin) 3 binds about 10-15%
Only the unbound (free) fraction 3 less than 1% of total thyroid
hormone 3 is biologically active and able to enter cells to exert
hormonal effects [5].
Peripheral Metabolism of Thyroid Hormones
The Rockwell approach emphasizes the critical importance of
peripheral thyroid metabolism, which is often overlooked in
conventional assessment models. T4 functions primarily as a
prohormone, requiring conversion to the more biologically active
T3 to exert most of its physiological effects [6].
This conversion occurs in peripheral tissues through the action of
deiodinase enzymes:
159
