India salt iodization

The preferred public health technology on the grounds of effectiveness and cost is universal salt iodization (USl). This means that all food industry salt for human (and animal) consumption should be iodized, which requires legislative action. The recommended level is 20 0 mg iodine/kg salt (WHO/UNICEF/ICCIDD, 1996). Such a measure has been adopted by many countries, including the highly populated countries, such as Bangladesh, China, India, Indonesia and Nigeria. 

To evaluate the effectiveness of salt iodization programs, a large-scale study was organized in 1956 for the prevention of Himalayan endemic goiter in India. A follow-up study in 1962 showed a marked decrease in goiter prevalence, while uptake and excretion of urinary iodine had become normal, indicating a state of normal thyroid. 

This chapter discusses the effect of iodization on normal thyroid physiology and hyperthyroidism over the period of time during which salt iodization was introduced in India. The effect on autoimmune thyroiditis has been discussed elsewhere in this book. 

No national-level data exists in India on the prevalence of Graves disease before or after the salt iodization program. 

There has been a substantial increase in iodine consumption by the population after the salt iodization program in India. 

In 1983, Hindustan Salt Limited was producing 0.2 million metric tons of iodized salt per annum. With the private sector entering the field, by 1990, there was a quantum leap in the quantity of iodized salt produced to 2.5 million metric tons annually. However, at that time, 962 salt iodization plants had been set up in India, with installed capacity for 12 million metric tons of iodized salt. Therefore, production was less than capacity, indicating insufficient consumer demand for iodized salt. In the absence of consumer awareness of IDD, many people were not willing to pay the extra cost for iodized salt. 

The difficulties in the production and quality maintenance of iodized salt for the millions who are iodine deficient, especially in Asia, were vividly demonstrated in India, where there was a breakdown in supply. These difficulties led to the adoption of universal salt iodization (USI) for India and subsequently for many other countries. This policy includes legislation to provide for compulsory iodization of all salt for human and animal consumption, and this legislation makes it illegal for noniodized salt to be available for human or animal consumption. 

Following this study, the government of India between 1962 and 1965, with the financial assistance of UNICEF, installed 12 iodization plants in different parts of the country. The concentration of iodate in salt was 25 ppm. lodate... 

Since the iodization of salt, there has been an increase in the daily consumption of iodine among the population, leading to a decrease in the prevalence of iodine deficiency disorders. In a survey (Toteja et ai, 2004) carried out on 1 45 264 children aged 6—12 years in 15 districts in India in 1997—2000, the goiter rate was found to have decreased to 4.78% as compared to a previous report of 21% in 1984—1986 (IGMR, 1989). Follow-up surveys carried out in the same region of the country over the period have shown a decrease in the prevalence of goiter over the years, as exemphfied by data from the National Capital Territory of Delhi (Table 87.1). 

By the early 1980s, the national goiter prevalence survey data demonstrated, however, that goiter was not localized, but rather affected all regions of India. In 1984, the Central Council of Health took the decision to iodize all edible salt throughout the country, and invited private sector participation in the production and distribution of iodized salt. USI was to be achieved completely in a phased manner by 1990. 

By 1999, The National Family Health Survey found that approximately 70% of India s population had access to iodized salt (UPS, 2000). However, of the 70% consuming iodized salt in India, only about half consumed salt that was adequately iodized (i.e., containing 15ppm of iodine at the household level) (UPS, 2000). Inadequately iodized salt was largely found in rural areas where access is the main obstacle. Approximately 57% of people living in rural areas and 64% of people within a low standard of living index consumed salt that was not iodized or iodized inadequately (UPS, 2000). 

Similarly in India, in a 1998-1999 survey the ICCIDD reported that 70% of the population consumed some sort of iodized salt. However, in a study (Gupta et al., 2006) of 175 healthy mothers and infants in New Delhi, 34%... 

The consumption of adequately iodi2ed salt was even lower, at 35% among people belonging to low socioeconomic stratas (LSES). Table 132.3 depicts the consumption of adequately iodized salt according to socioeconomic status in India (National Family Health Survey-2, 2000). 

Table 132.3 Consumption of adequately iodized salt according to socioeconomic status in India during 1998-1999...

Before providing data from India, it is relevant to summarize the information from other countries recently making the transition from an iodine-deficient to an iodine-sufficient state. Studies from Greece, Turkey and Iran report an increase in the prevalence of antithyroid peroxidase antibodies in the population after iodine supplementation (Zois et ai, 2003 Bastemir et aL, 2006 Heydarian et ai, 2007). Interestingly, other studies have provided data to the contrary. For example, the introduction of iodized salt to severely iodine-deficient children did not provoke thyroid autoimmunity in a study conducted in Morocco (Zimmermann et ai, 2003). 

It was then shown that the correction of iodine deficiency before pregnancy would prevent or eliminate this brain damage. This finding provided the basis for India s program for the elimination of brain damage caused by iodine deficiency by the use of adequately iodized salt. 

What is now needed is the coming together of policy makers and the scientific fraternity - together they can start an odyssey into the future, ably supported by our partners in the private sector and the iodized salt producers, toward an India devoid of IDD and a healthy society, thus fulfilling the right of every child to attain optimal physical and mental development. 

Unfortunately, these simple protective measures are not implemented everywhere in the world. In India, an estimated 250,000,000 people suffer from iodine deficiency and the accompanying lethargy and decrease in motor skills and mental acuity. About nine million babies are bom with cretinism annually. Salt is often sold in big chunks, because in this form it resists humidity better. The only way to iodize the salt chunks is to spray them with a solution of potassium iodate. This, though, makes the large salt crystals look dirty, so people often wash them off before crushing them. They don t realize that cleanliness is not always a virtue. 

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