Iodine Deficiency

IODINE is an essential micronutrient for humans. Even animals and plants need it.

Iodine deficiency constitutes the world's major cause of preventable mental retardation ranging from mild intellectual blunting to overt cretinism.

Thyroid gland produces two hormones - thyroxine (T4) and tri-iodo-thyronine (T3). Iodine is used for the production of these hormones. Iodine also helps in the growth of new cells in the foetal life.

Effects of iodine deficiency.
Enlargement of the thyroid - goitre
Cretinism
Mental retardation.
Subtle iodine deficiency affects the woman's ability to have a pregnancy, increases foetal loss.
Leads to a lack of concentration, poor memory and sluggishness.

When the availability of iodine is low, the thyroid gland grows bigger and bigger. Iodine deficiency is the major cause of endemic goitre.
Neck irradiation for lymphnode malignancies, radiation exposure following nuclear accidents and even repeated X-Rays of the neck increase the risk of thyroid cancer in subjects with iodine-deficient goitres. Follow-up studies of the Chemobyl nuclear plants disaster have confirmed the risk of thyroid cancer from a nuclear accident.
Iodine deficiency during reproductive age may cause inability to conceive. Higher rates of pregnancy loss and, most importantly, mental retardation and various neurological manifestations in the newborn are well-known sequelae of iodine deficiency.

While iodine deficiency early in pregnancy accounts for neurological cretin that occurring later in foetal life and continuing through out infancy leads to a profound decrease in thyroid functions, resulting in a myxodernatous cretin.

Unlike other nutrients such as iron, calcium, zinc or the vitaniins, iodine does not occur in sufficient concentration in natural foods. Small quantities of iodine are present in vegetables and drinking water. Deforestation and soil erosion increase the loss of iodine from the soil. Desalinated sea water and seafoods (prawns, fish crabs, snails, etc.) have higher quantities of iodine.
Soils from mountain ranges such as the Himalayas, the Alps and the Andes are areas devastated with frequent floods; these are iodine deficient. Hence, ground or surface water in these areas are iodine deficient.
The contamination of sea water by industrial and other organic wastes have significantly reduced iodine availability in our sea foods.

Dietary iodine supplementation has, therefore, become essential.

Potassium iodate is used for the iodinsation of refined salt. The level of iodisation at the production level is 30 mg per kg salt, aiming at providing an individual 30O ug of iodine in 10g of salt consumed.

Iodine being a volatile substance is rapidly lost from the iodised salt when it is kept open, near a fire place and or is added while cooking. A fresh packet of iodised salt should be obtained every month, stored away from the fireplace and added to food items after cooking.

The fear of harmful effects of iodine is totally unjustified. The use of iodised salt by people with iodine-sufficient status produces no hann. Iodised salt should be avoided by patients with thyrotoxicosis.