Iodine Disorders

INTRODUCTION
Iodine deficiency disorders are still very much prevalent in the world today. Two billion people, estimated by the WHO, still lack a sufficient level of iodine in their diets which leads to a range of disorders known as iodine deficiency disorders (IDD).
So what is iodine? Iodine is an essential micronutrient in the diet which is used by the thyroid gland (located in the throat) to produce thyroid hormones which help control the body’s metabolism. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3).
Thyroxine has four iodine molecules attached to it’s structure, while triiodothyronine has three iodine molecules attached to it.
Iodine deficiency has a major negative effect on growth and
The most severe disorders caused by iodine deficiency is cretinism. This condition occurs when the iodine intake is below 25μg/day. Cretinism, in it’s most common form, has typical features of either a predominant neurological syndrome with severe to intense mental retardation. This includes deaf-mutism (speech and hearing defects) squint and disorders of stance and gait of varying intensity. Myxedematous cretinism, which is less common, shows predominant features of hyperthyroidism and dwarfism with less severe mental
Thyroidal uptake of radioiodine reaches its maximum value in the infancy years and then declines progressively into adult life. It was estimated that the turnover rate for intra-thyroidal iodine must be 25 to 30 times higher in young infants than the rate in humans over 12 years old. In iodine deficiency a further increase in turnover rate is required to maintain normal thyroid hormone levels. This is the reason for a greatly increased susceptibility of the infant to iodine deficiency. Iodine deficiency also causes increased uptake of radioiodide resulting from exposure to nuclear radiation, as occurred in the Chernobyl disaster. Protection against this increased uptake can only be provided by correction of iodine deficiency in the