Thyroxine (T4) is named after the four molecules of iodine attached to it. Thyroxine (T4) is converted into the more active form of the hormone called triiodothyronine (T3). Approximately 20% of thyroxine (T4) is converted to triiodothyronine (T3) in the intestines, but only in the presence of friendly flora such as Lactobacillus acidophilus and Bifidobacteria. The conversion of T4 to T3 is also dependent on the presence of iodine, selenium, zinc and tyrosine, as well as other nutrients. Elevated levels of T4 are associated with symptoms such as anxiety, insomnia, diarrhea, and muscle aches and pains. Low levels of T4, known as hypothyroidism, are associated with symptoms such as depression, weight gain, dry skin, hair loss, constipation and cold intolerance. Many factors may disrupt the balance of thyroid hormone production, including medications, allergies (wheat & gluten), anemia, poor gastrointestinal function, insulin resistance, bone metabolism, hormone imbalances, nutrient deficiencies such as selenium, decreased levels of Vitamin A & D and metabolic disruptors such as PCBs to name a few.
Test Preparation For Optimal Results:
If possible, have the lab collected early in the morning or shortly after waking. For comparison purposes, have subsequent labs collected close to the same time.
Disclaimer: Your health care provider should evaluate a deviation from normal ranges.