Thyroid Hormone Synthesis:
Thyroid gland is a butterfly shaped gland located just
inferior to the larynx (neck). Thyroid
is the only endocrine gland that stores and synthesizes Thyroid Hormone. Thyroid
hormone regulates metabolic activity of our body.
Trapping Iodine from blood is the first step for Thyroid
Hormone synthesis. Thyroid follicular cells produces two type of hormone based
on presence of Iodine atom: Thyrosin or tetraiodothyrosine (T4) as it contains
four iodine atoms and Triiodothyrosine (T3) which contains three atoms of
iodine, T3 and T4 together form thyroid hormone.
Thyroid gland works by trapping (I-) Iodide ions
and its active transportation from blood into the thyroid follicular cells. As
a result, thyroid gland contains most of the iodide of the body. Iodide is then
oxidized to form Iodine atom. Simultaneously, follicular cells are also
synthesizing Thyroglobulin (TBG). Thyrosine amino acid of TGB is iodinated and
further coupling of diiodotyrosine molecules and/or iodotyrosine forms thyroid
hormones (T3, T4). More than 99% of T3
and T4 combine with protein in the blood.
Role of Thyroid
Hormone:
- Synthesis of Protein
- Carbohydrate and fat metabolism
- Increase number and activity of mitochondria
- Glucose absorption in body
- Maintain BMR (Basal metabolic rate)
Why is it necessary to maintain iodine level?
Iodine is not made in our body naturally, so it should be essential part of our diet. Absence of enough Iodine, affects production of thyroid hormone. The Institute of Medicine has set the Recommended Dietary Allowance (RDA) for iodine in adult men and women at 150 μg per day.
Iodine Rich Food Source
a. Cheese d. Iodized table
salt g. Potatoes j. Seaweed
b. Shellfish e. Soy milk h. Soy sauce k.Yogurt
c. Eggs f. Spinach i. Oats l. Kidney beans
Written By: Richa Chaturvedi
