By Lesley Oakes, Naturopath
The thyroid gland produces the hormone called thyroxine, which is also known as T4. T4 must be converted in the body into the active form of thyroid hormone called triiodothyronine, known as T3.
The active form of thyroid hormone (T3) directly stimulates the energy factories inside the cells to burn calories at a faster rate.
In some people however, the body is not capable of converting the T4 into the active form T3 and their energy levels decline and their metabolism slows down.
The most common cause of this conversion block is iodine deficiency. It is important to have your iodine levels checked. A 24-hour urine iodine-loading test is the best way to determine how much iodine your body needs. Australian soils are noticeably deficient in iodine and many women in particular are iodine-deficient as a result of this. Even with a seemingly healthy diet, it is easy to miss this key element.
Other factors that can block the T4 to T3 conversion include:
- Elevated cortisol levels due to chronic stress
- Nutritional deficiencies (vitamins C, B and D and magnesium)
- Toxins such as heavy metals including mercury and lead
- Commonly prescribed drugs (beta blocker and antidepressants).
Without performing the proper thyroid laboratory tests that include T4 and T3 and not just TSH (Thyroid Stimulating Hormone from your pituitary gland), this conversion block will not be recognised. Fatigue, unexplained weight gain, especially in middle age, weak hair and nail strength and dry skin are all possible indicators that you are iodine-deficient.
If you think these problems relate to you, then make an appointment for reliable iodine testing and assistance in this area.