Normal Function of the Thyroid Gland
The function of the thyroid gland is dependent on the intake of Iodine to make thyroxine (T4) and tiiodothyronine. The thyroid cells absorb iodine from the blood stream which binds with the amino acid tyrosine. After creation they are released into the blood stream to control metabolism, conversion of oxygen and more. Every cell in the body depends on thyroid hormone for regulation. The normal thyroid produces 80% T4 and 20% T3. This seems to be the reason why synthetic thyroid hormones such as Synthroid, Levoxyl and Levothyroxine are problematic for thyroid less or very low functioning thyroids.