How to reduce/prevent mental retardation-
Iodine deficiency is the key factor

Columnist MUHAMMAD ANWAR KHAN says that iodine deficiency has become a major health problem.

Iodine is a dark-gray to purple-black, lustrous, solid element with a rhombic crystalline structure. It is the least active of the Halogens which are found in-group VII a, of the Periodic Table. It is normally diatomic, i.e., it has two iodine atoms in each molecule, in the solid, liquid, and vapour states. When heated, it passes directly from the solid to the Vapour State (sublimation), the vapour having an intense violet colour and a characteristic-irritating odour. Iodine is only slightly soluble in water but dissolves readily in a solution of sodium or potassium iodide. Tincture of iodine, is a solution of iodine and potassium iodide in alcohol. Iodine also dissolves in carbon disulfide, carbon tetrachloride, and chloroform, giving a deep violet solution. Iodine forms many compounds. With hydrogen, it forms hydrogen iodide, which in water solution becomes Hydroidic acid. It forms compounds with certain nonmetals (e.g., carbon, nitrogen, phosphorus, and oxygen) and with most metals. Iodine is displaced from its compounds by the other halogens. The element is obtained from salt deposits, as from the saltpeter beds where it occurs in small quantities as an Iodate, and from the salt brines associated with some oil wells .It is also found as an iodide in the ash of certain seaweeds. Iodine may be prepared by displacement from its compounds with chlorine. Treating an iodide with manganese dioxide and sulfuric acid sublimes the iodine. Iodine is important in medical treatment; tincture of iodine and Iodoform are widely used.
Iodine is employed in the preparation of certain drugs and in the manufacture of some dyes. Silver iodide, a yellow salt, is used in photography; it is water insoluble and turns black when exposed to light. Starch turns deep blue (almost black) in the presence of a small amount of iodine; this reaction serves as a test for either starch or iodine. Iodine is essential to human nutrition. Iodine 127; it is the only isotope of iodine occurring in nature, although 24 iodine isotopes are known. Iodine 131 is a radioactive isotope with a half-life of 8 days. It is used medically to diagnose abnormalities of the thyroid gland. It is also a component of fallout produced by nuclear explosions. Bernard Courtois discovered iodine in 1811.
In this article, the emphasis will be on its need in human body.
Iodine deficiency is a major global health problem and its consequences can be very devastating. Insufficient consumption of iodine was and still is the most prevailing and most preventable cause of brain damage, anywhere around the world. However, the situation obtaining in the developing world is more alarming than in the developed world.
Once growth of brain is affected adversely, the process is irreversible through known medication to date. Its importance therefore, cannot be too strongly emphasised. Given proper attention the incidence of mental retardation can be reduced substantially and may also be prevented.
There are a number of causes for mental retardation, which may start from pregnancy and can occur after birth. By taking steps to ensure that the adults (particularly pregnant mothers) and children do not suffer from iodine deficiency, incidence of mental retardation can be reduced/prevented.
It is unfortunate that in Pakistan no distinction is made between mental illness and mental retardation, although the two are different from each other and each needs separate attention and services. It is also to be kept in mind that while mental illness can now be cured, mental retardation is an irreversible process. Mental retarded persons need attention, care and guidance throughout their lives. Only those families who have mentally retarded persons know what it means to live with them. There are at least 5 million handicapped persons in Pakistan and so at least 5 million families are involved. If by addressing the problem of iodine deficiency we can avoid some addition in their population, effort and money spent for this purpose should be worthwhile.
Lack of this mineral is also a leading cause of stillbirths, miscarriages and cretinism, the experts from the World Health Organization and UNICEF say that even cases of slight iodine deficiency can hamper the growth of children’s brains, shaving up to 15 points off their IQs and causing widespread learning disabilities. The first 5 years of a child’s life is of crucial importance and needs close watching.
About 1 billion people worldwide appear to be susceptible to health problems stemming from iodine deficiency. This will indicate importance of the product throughout one‘s life.
Iodine deficiency is common. One does not need an expensive test to determine if one is deficient in this. All one needs to do is to get a bottle of tincture of iodine from a drug store and paint a 3-inch patch on one ‘s skin (arm or belly). Be careful not to drop any on clothes, as it will stain clothes. The stain should last for 48 hours. The sooner it disappears, the more profound will be iodine deficiency.
Iodine is an essential trace element for humans. The average adult body contains between 20 and 50 mg iodine, and more than 60 per cent of this is concentrated in the thyroid gland situated at the base of the neck. The rest is in thyroid hormones in the blood, ovaries and muscles. Iodine is a component of the thyroid hormones triodothyronine and thyroxin, which determine the metabolic rate of the body. This effects the body’s conversion of food into energy and also the way energy is used.
Thyroid hormones are vital for growth and development of all organs, especially the brain, reproductive organs, nerves, bones, skin, hair, nails and teeth. The thyroid is involved in protein manufacture, cholesterol synthesis, carbohydrate absorption and the conversion of carotene to vitamin A. Thyroxin is an important regulator of body weight. Iodine is rapidly absorbed from the gut. Excesses are excreted in the urine.
When body iodine stores are exhausted, the thyroid gland in the neck is influenced by the pituitary gland to increase its activity and can become enlarged. This swelling is known as a goiter. Other symptoms of hypothyroidism include fatigue, apathy, drowsiness, sensitivity to cold, lethargy, muscle weakness, weight gain and coarse skin. Young men and women in iodine-deficient areas are at the greatest risk of developing goiter and other illnesses stemming from iodine deficiency.
A reduction of salt in the diet, combined with a growing consumption of manufactured food prepared using low iodine salt, may lead to an increased risk of deficiency in areas where there is little natural iodine.
Severe iodine deficiency in a mother’s diet during pregnancy increases the risk of miscarriage and stillbirth. If the baby survives, it is likely to suffer irreversible mental retardation. This is known as cretinism and is a major cause of preventable intellectual impairment in low iodine areas. Mildly iodine-deficient children have learning disabilities and poor motivation. The developing fetus, newborn and young children are most susceptible to the effects of an iodine- deficient diet and treatment before conception or in early pregnancy is essential to prevent irreversible damage. Breast milk contains more iodine than formula milk and premature babies who are formula-fed may be at risk of deficiency.
Iodine deficiency may play a role in fibrocystic breast disease. Hypothyroidism and iodine deficiency may also increase the risk of breast cancer, as a higher incidence of disease has been found in iodine-deficient areas.
Good sources of iodine include vegetables grown in iodine-rich soil, kelp, onions, milk, milk products, salt-water fish and seafood. The iodine content of vegetables varies widely with the iodine content of the soil in which they are grown. Symptoms of acute poisoning from ingestion of iodine (rather than iodide) are mainly due to its corrosive effects on the gastrointestinal tract and include vomiting, abdominal pain and diarrhea. Other symptoms may include metallic taste, sore teeth, gum and mouth, and severe headache. Eventually, the kidneys fail to produce urine. 2 to 3 g of iodine should be avoided as it can prove to be fatal. Treatment is with large volumes of milk and starch solutions with 1 per cent solution of potassium thiosulfate.
Toxic effects from the iodide form of iodine are rare and may include a reduction of thyroid hormone secretion, acne, and inflammation of the salivary glands when doses reach 1500 mcg. Dietary intake of iodine should not exceed 1000 mcg per day for any length of time. Toxic symptoms may result from high intakes, which occur as part of medical treatment with iodine as iodides. Patients may become hypersensitive after prolonged oral administration.
Topical application of iodine-containing disinfectants may lead to hypothyroidism in newborn babies. A disorder known as Hyperthyroidism of Graves disease is due to an overactive thyroid. It is not due to over-consumption of iodine, but happens as a result of disruption in the mechanisms that control thyroid hormone function.
Supplemental iodine is used to treat iodine deficiency disorders. On a large scale, this is often given in the form of iodised salt or as an iodised oil injection. Iodine is an antiseptic and can be used to kill bacteria and fungi. Iodine used topically, as a douche is effective against a wide range of organisms including Candida and Chlamydia. Excessive use should be avoided since some iodine will be absorbed into the system and can cause suppression of thyroid function. Iodine tablets are frequently used to disinfect water. Iodine can also be used to prevent radioactive damage to the thyroid gland. In nuclear accidents, radioactive iodine is released into the atmosphere and can be taken up by the thyroid, possibly causing cancer. Immediate treatment with iodine prevents this uptake.
Potassium iodide supplements should be used with caution in cases of dehydration, acne, heat cramps, adrenal insufficiency, and cardiac disease. Prolonged use during pregnancy is not advisable.
Age wise recommended dosage is as follows:

 50 micrograms for infants (first 12 months of age)
 90 micrograms for children
(2-6 years of age)
120 micrograms for school
children (7-12 years of age)
 150 micrograms for adults (beyond 12 years of age)
 200 micrograms for pregnant and lactating women

Iodine is found in the soil. Hence, depending on the amount of iodine that exists in the soil, it will be absorbed by plants and animals as they eat their food. Seafood usually is a reliable source. Dairy products, meat, and poultry usually have moderate amounts of iodine, but it depends on how the animals are fed. In most developed countries animals are supplemented, but this may not be the case elsewhere. Some prepared foods have iodine added in the salt.
The other sources of iodine aside from iodised salts are:
Iodised oil, food colouring (may not all be bio-available, however); vitamin supplements; medications (e.g., Amiodarone); topical antiseptics (e.g. Povidone Iodine); some commercial bread (Iodate added as a conditioner, but in the US this technology has changed); iodine treatments for domestic animals (e.g., for footrot, etc); water purification tablets; many other sources not well identified Excess of Iodine is excreted and most people can tolerate fairly large amounts without problems. People with a tendency towards autoimmune thyroid disease (Graves’ Disease, Hashimoto’s Thyroiditis), are less tolerant. Up to a milligram of iodine is probably safe for almost everyone. However, if an individual has previously been iodine deficient, he/she may be at risk for iodine-induced hyperthyroidism when the iodine deficiency is corrected; this occurs most typically in older subjects with thyroid nodules. The hyperthyroidism can usually be treated satisfactorily.
How much Iodine in Iodised salt is destroyed while cooking depends on the cooking conditions and the salt. Potassium iodide (KI), used in the US, Canada, and much of northern Europe, is more likely to be lost than potassium Iodate (KIO3), which is used in most of the developing world. Conditions of acidity and other contents of the cooking pot can have an effect. In general, boiling salted water with KIO3 gives fairly little loss.
Storage of Iodine depends on conditions of storage (heat, humidity, exposure) and purity of salt. The range is so great that one can answer this only for specific conditions. In the US, iodised salt is fairly stable and little is lost in storage under normal conditions.
If one takes large amounts of salt and if the salt has inappropriately high iodine content, or if one is at risk for iodine-induced Hyperthyroidism, for most people, even the fairly high amounts of iodine in salt (about 76 mcg/g) are not going to give problems; most people do not eat more than 10 g salt per day. If we take 1000 mcg iodine per day as a safe level, then iodised salt is unlikely to provide that high amount. Of course, if one is getting large amounts of iodine from other sources as well, the effect is additive.
Salt being essential ingredient of food is considered the best way of correcting iodine deficiency by adding iodine to it in measured doses, and those who wish to avoid use of salt can resort to seafood. In this connection it may be relevant to point out that whereas 1/4 of teaspoon of iodised salt provides 95 micrograms of iodine, 6ounce portion of sea fish provides 650 micrograms of iodine. Therefore, apart from iodised salt, people can use seafood, seaweed and plants grown in iodine rich soil.
In Pakistan the problem of iodine deficiency has been receiving attention for quite some time. Efforts have also been made to popularise the use of iodised salt but it is understood that manifold problems have been experienced with the salt processors particularly with small crushing units of rock salt, who cannot be relied upon to add measured doses of iodine to the crushed salt. Another problem that has been experienced is with the dietary habits of people, which have been found difficult to change.
If we are to make a headway in the programme, it is important that all aspects of the problem are examined in depth and fresh programmes are prepared. Before accepting salt, as the only vehicle for adding iodine, other vehicles should also be considered, such as milk, bread, flour and condiments.
The situation is serious and we do not appear to have achieved much success in earlier campaigns. Mental retardation and other Iodine deficiency related ailments are on the increase. As such, the sooner the Nation gives attention to this matter, the better. Political elements in the country also need to be involved for taking steps to address the vital issue of Iodine Deficiency.