Iodine – Essential for Health

Iodine Deficiency Disorders (IDD) continue to pose a serious threat to the health, well being, economic productivity and advancement of several hundred million people worldwide. People living in iodine deficient environment suffer from reduced mental and physical abilities, cretinism, deaf-mutism, squint, still-birth, abortion, goitre of all ages, neuro-motor defects, etc. Even when born normal, young children whose diets are low in iodine have their lives trapped in mental dullness and apathy. IDD preys upon poor, pregnant women and preschool children, posing serious public health problems in more than hundred developing countries. Iodine deficiency was once considered a minor problem, causing goiter, it is now known that it affects developing brain much deadlier and thereby, constituting a threat to the social and economic development of many countries.

The magnitude of the IDD problem is quite high. This has led to an International focus on elimination of Iodine Deficiency Disorders and October 21 is observed as the Global Iodine Deficiency Disorders Prevention Day to create awareness towards this problem. Iodine is an essential component of thyroid hormones which are needed for optimal mental and physical development and regulation of body metabolism. Therefore, in iodine deficiency populations, it is critical to have effective universal salt iodisation. Iodine, a chemical element like carbon, oxygen or iron, is available in fairly constant amounts in seawater while it is found in an uneven distribution over land and fresh water.

It is an essential part of the chemical structure of thyroid hormones. It makes two hormones - thyroxine (T4) and triiodothyronine (T3). The thyroid hormones act in target organs by influencing many different chemical reactions, usually involving manufacture of key proteins. The body must have proper levels of thyroid hormone to work well. Recommended daily intake of iodine varies with age. To meet iodine requirements, the recommended daily intakes are - 50 micrograms for infants (first 12 months of age), 90 mg for children (2-6 years of age) 120 mg for school children (7-12 years of age), 150 mg for adults (beyond 12 years of age) and 200 mg for pregnant and lactating women. Most of it comes from what we eat and drink. Seafood is usually a good source because the ocean contains considerable iodine. Freshwater fish reflect the iodine content of the water where they swim.

Iodine contents in other foods vary depending on their source. Plants grown in iodine-deficient soil do not have much iodine, nor do meat or other products from animals fed on iodine-deficient plants. Iodized salt is a special case. With only a few isolated exceptions, edible salt (sodium chloride) does not naturally contain iodine. Iodine is added deliberately as one of the most efficient ways of improving iodine nutrition. Iodine exposure can come from many other sources too, for example certain food colorings (erythrosine), skin disinfectants, such as povidone iodine, is absorbed and reaches the bloodstream, health foods – certain types of kelp, dyes and medicines. People also get iodine from its use in farm animals, for cleansing udders or as part of iodine-containing medicines. Iodate has been used as a bread stabilizer in commercial baking, although this practice is less common now.

Though iodine deficiency has terrific negative effects, its excess can play havoc too. The excess of it causes thyroid under activity. Iodised and uniodised salt are sold simultaneously in the country. But the awareness of the health priority aspect of iodised salt among the public has resulted in the creation of a significant consumer demand for iodised salt. The World over, including China and the neighbouring countries like Bangladesh, Bhutan, Sri Lanka, Nepal, Maldives, Myanmar, Thailand, etc., are implementing compulsory salt iodisation for human consumption. Globally iodated salt is recognized as the cheapest and most sustainable way to prevent and control Iodine Deficiency Disorders.

Except few types of goiter, most of the iodine deficiency disorders are irreversible and permanent in nature, but they can be easily prevented by regular consumption of iodated salt daily. Realizing the magnitude of the problem, the Government launched a 100 per cent centrally assisted National Goitre Control Programme (NGCP) in 1962. In August 1992, the National Goitre Control Programme (NGCP) was renamed as National Iodine Deficiency Disorders Control Programme (NIDDCP) with a view to cover a wide spectrum of Iodine Deficiency Disorders. The Government’s goal of NIDDCP is to reduce the prevalence of Iodine deficiency disorders below 10 per cent in the entire country by 2012 A.D.