Iodine

Iodine is an essential micronutrient. It is required for the synthesis of the thyroid hormones, thyroxine and triiodothyronine. Iodine is essential in minute quantities for the normal growth and development and well being of all humans.

Sources: sea foods(sea fish, sea salt) and cod liver oil

Goitrogens: These are chemical substances leading to the development of goitre. they interfere with iodine utilization by the thyroid gland.The brassic group of vegetables(eg., cabbage, cauliflower) may contain goitrogens. Most important among the dietary goitrogens are probably cyanoglycosides and the thiocyanates.

Spectrum of IDD in order of increasing severity:

Disorders	Levels of severity
goitre	grade I grade II grade III
hypothyroidism	varying combination of clinical signs
subnormal intelligence delayed motor milestones mental deficiency hearing defects speech defects	variable severity
strabismus	unilateral or bilateral
nystagmus
spasticity	spastic diplegia, spastic quadriplegia
neuromuscular weakness	muscle weakness in legs, arms, trunk
endemic cretinism	hypothyroid cretinism, neurological cretinism
intrauterine death(spontaneous abortion, miscarriage)

In 1992, the Central Council of Health, took a policy decision to iodize the entire edible salt in the country by the year 1992. In August 1992, the NGCP was renamed as National Iodine Deficiency Disorders Control Programme (NIDDCP) taking into its ambit control of the wide spectrum of IDD like mental and physical handicap and reproductive wastage. The Goal of the NIDDCP is to reduce the prevalence of IDD below 10% in endemic districts of the country.

The programme has the following components;

• Surveys to assess the magnitude of Iodine Deficiency Disorders
• Production and supply of iodised salt to the whole country
• Health education and publicity
• Resurvey in the goitre endemic areas after 5 years of continuous supply of iodised salt, to assess the impact of the control programme
• Laboratory monitoring of iodized salt and urinary iodine excretion

1.Iodized Salt: The iodization of salt is now the most widely used public prophylactic measure against endemic goitre. In India, the level of iodization is fixed under the Prevention of Food Adulteration (PFA) Act and is not less than 20 ppm at the production point and not less than 15 ppm at the consumer level. Under the NIDDCP, the Govt of India proposed to completely replace common salt with iodized salt in a phased manner.

Another method which has demonstrated its efficacy for controlling goitre is intramuscular injection of iodized oil(mostly poppy-seed oil).

2.Iodine monitoring: a network of laboratories have been set up across the country for iodine monitoring and surveillance. These laboratories are essential for: a)iodine excretion determination, b)determination of iodine in water, c)determination of iodine in salt for quality control.

3.Manpower training: It is vital for the success of the IDDCP that health workers and others engaged in the programme be fully trained in all aspects of goitre control including legal enforcement and public education.

4.Mass communication: Mass communication is a powerful tool for nutrition education. It should be fully utilized in goitre control work. Activities through song and drama division have been taken up in 8 states viz., UP, Bihar, Rajasthan, Madhya Pradesh, Orissa, Chattisgarh, Jharkhand and Uttaranchal. Besides this, activities are being carried out through 268 units of the Directorate of Field Publicity in nearly 500 districts.The activities include film shows, group discussions and other special programmes. IDD spots are also being telecast at prime time through the national network of Doordarshan and AIR. DAVP has been actively involved in bringing out messages in the newspapers, radio spots and print materials in the form of posters and pamphlets.

Hazards of iodization: A mild increase in the incidence of thyrotoxicosis has been observed following the implementation of IDDCP.