Clinical Nutrition

Lesson 8: Iodine deficiency disorders

Functions

Iodine functions as an integral part of the thyroid hormones which regulate the key processes in various cells of the body. The thyroid hormones are required for the normal growth and development of individual tissues, for maturation of the whole body, for energy production, oxygen consumption in cells and for maintaining the body’s metabolic rate. If thyroid hormone secretion is not adequate, the basal metabolic rate is reduced and the level of activity of the individual is decreased (hypothyroidism)

The function of iodine in the body is to help synthesise thyroid hormones – thyroxin (T4) and triiodothyronine (T3). The synthesis, release and action of these hormones is regulated very finely as either excess or deficiency of these hormones will be detrimental to normal body functioning. The thyroid gland has to receive around 60µg of iodine per day to maintain an adequate supply of thyroxin.