The thyroid is a small, butterfly-shaped gland located in the front of the neck that produces hormones, notably thyroxine (T4) and triiodothyronine (T3), which stimulate vital processes in every part of the body. These thyroid hormones have a major impact on the following functions:
- Use of energy and oxygen
- Heat production
- The use of vitamins, proteins, carbohydrates, fats, electrolytes, and water
- Immune regulation in the intestine
These hormones can also alter the actions of other hormones and drugs.
Iodine and Thyroid Hormone Production
Regulating thyroid function is a complex and important process that involves several factors, including iodine and four thyroid hormones. Any abnormality in this intricate system of hormone synthesis and production can have far-reaching consequences on health.
Iodine. An understanding of the multi-step thyroid hormone process begins with iodine. Eighty percent of the body's iodine supply is stored in the thyroid. Iodine is the material used to make the hormone thyroxine (T4).
Thyroid Hormones. Four hormones are critical in the regulation of thyroid function:
Review Date: 05/03/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.