Iodization, salt

Iodized Salt. Iodized table salt has been used to provide supplemental iodine to the U.S. population since 1924, when producers, in cooperation with the Michigan State Medical Society (24), began a voluntary program of salt iodization in Michigan that ultimately led to the elimination of iodine deficiency in the United States. More than 50% of the table salt sold in the United States is iodized. Potassium iodide in table salt at levels of 0.006% to 0.01% KI is one of two sources of iodine for food-grade salt approved by the U.S. Food and Dmg Administration. The other, cuprous iodide, is not used by U.S. salt producers. Iodine may be added to a food so that the daily intake does not exceed 225 p.g for adults and children over four years of age. Potassium iodide is unstable under conditions of extreme moisture and temperature, particularly in an acid environment. Sodium carbonate or sodium bicarbonate is added to increase alkalinity, and sodium thiosulfate or dextrose is added to stabilize potassium iodide. Without a stabilizer, potassium iodide is oxidized to iodine and lost by volatilization from the product. Potassium iodate, far more stable than potassium iodide, is widely used in other parts of the world, but is not approved for use in the United States. 

If the necessary iodine input is insufficient the thyroid gland enlarges in an attempt to gamer more iodine addition of 0.01% Nal to table salt (iodized salt) prevents this condition. Tincture of iodine is a useful antiseptic. 

Iodide or iodate are used to iodize salt. The level of salt iodization depends on per capita salt consumption, moisture, light, heat, and contaminants. The recommended daily iodine requirements are 50 pg for infants, 90 pg for children (2-6 yrs), 120 pg for schoolchildren (7-12 yrs), 150 pg for adults and 200 pg for pregnant and lactating women. 

WHO/UNICEF/ICCIDD. Indicators for assessing iodine deficiency disorders and their control through salt iodization. Geneva (Switzerland) World Health Organization 1994. (WHO/NUT/94.6). 

Iodine is concentrated in humans by the thyroid gland to form the iodo-amino acid thyroxine, which is essential to normal health and development. Iodine is a rather rare element (crustal abundance 0.00003 weight %, cf. Table 1.1), so the thyroid gland has become very efficient at scavenging iodide ion. As iodine is deficient in the diet in some locations, a small amount of iodide ion is routinely added to commercial table salt ( iodized salt ). 

Palatability Trials. Two to five sheep were placed in a pen containing a feeder with four movable compartments. The compartments were numbered and their positions randomized each day. Two feeds were compared in each pen. Each day a known amount of feed was placed in each compartment and the position was determined at random. Twenty-four hours later the refusals were removed, weighed, and fresh feed added. A normal test period was seven days. The first trial was designed to determine the relative palatability of hemicellulose and molasses. The basal ration consisted of timothy hay, 68% com, 28.16% 44% CP soybean oil meal, 2.31% urea, 0.77% dicalcuim phosphate, 0.26% salt, iodized, 0.50% and vitamin A and D concentrate to meet NRC requirements. Other rations were prepared by removing com and increasing the soybean meal and adding 5% dry matter from cane molasses, LHC, dried molasses, or dried LHC. 

The rations all contained soybean meal, 13% dicalcium phosphate, 0.7% salt, iodized, cobaltized, 0.5% Vitamin A and D premix, 0.3% sodium propionate (as a mold inhibitor), 0.2%. 

From these limited examples, it appears that the knowledge level of iodine nutrition varies virtually from one extreme to the other in different countries. These variable knowledge levels have the potential to impact not only on the iodine status of the population, but also on the sustainability of national salt iodization programs. Because knowledge of iodine nutrition is viewed as one of the important determinants in the success of salt iodization programs, we take an in-depth look at the fundamentals of iodine knowledge in this chapter. 

In the case of iodized salt, the process phase starts at the point of salt iodization and comprises the whole chain of events, which includes storage, transport, and distribution at wholesale and retail levels, and extends to the point of consumption at the household level. Factors operating at any point in this chain of events and infiuencing or determining the amount of iodine eventually consumed at household level are considered process factors, and are assessed in terms of the process indicators. Of these indicators, the iodine content of iodized salt at the point of iodization, at the retail level and in the household represent the process indicators most commonly assessed in surveys. 

Iodine-containing processed foods, such as bread, fish sauce and other foods, play an increasingly significant role in dietary iodine intake in many populations. It has even happened that producers of processed foods use iodized salt unknowingly (Harris et ai, 2003). The practice of processed foods containing iodine has grown to the extent that, in some countries with voluntary salt iodization, iodine-containing processed foods may be the primary source of dietary iodine intake. 

Universal salt iodization (USI) is the main intervention strategy for iodine deficiency control, and was adopted by the International Conference on Nutrition in 1992, reaffirmed by the World Heath Assembly in 1993, and established as a World Summit for Children mid-decade goal in 1995- Salt has been chosen as a vehicle, because of its widespread consumption and the extremely low cost of iodization. In high-risk areas, where populations cannot... 

Regular monitoring of iodi2ed salt quality and population iodine status is important to ensure that salt iodization is effective in the prevention and control of iodine deficiency, and that it does not expose susceptible groups to levels of iodine intake that are too high. 

The preferred strategy being used to efiminate IDD as a pubhc health problem is salt iodization universal... 

It has also been mentioned that salt iodization efficacy, the preferred strategy for IDD, might be influenced by ID, because this disorder impairs thyroid metabolism (WHO, 2001, Zimmermann et al., 2000). It has been observed that two initial steps in thyroid hormone synthesis are catalyzed by Fe-dependent thyroid peroxidase (TPO). One Fe-defl-ciency anemia study in rats showed reduced TPO activity, and decreased plasma T4 and triiodothyronine (T3) levels (Hess et al, 2002). IDA may also alter the central nervous systems thyroid metabolism control, and reduce T4 to T3 peripheral conversion (Beard etal, 1998), modify nuclear T3 binding (Smith et al, 1994), and increase circulating thyrotropin (TSH) (Beard et at, 1990). The therapeutic response to oral iodized oil is impaired in children with IDA compared with Fe-sufficient children (Zimmermann et al, 2000). 

We will analyze those thyroid cancers that were shown to have undergone changes in their incidence after the implementation of iodine prophylaxis in different endemic goiter areas, probably through the effect of dietary iodine in relation to serum thyrotropin (TSH) levels and increase of thyroiditis, as well as in relation to the standard of medical care. We will also focus on the effect of salt iodization... 

Note-. PC, papillary carcinoma FC, follicular carcinoma UC, undifferentiated carcinoma MC, medullary carcinomas TL, thyroid lymphoma NA, not applicable (TL none in males and before salt iodination, MC two and three cases before and after prophylaxis, respectively). Thyroid cancer by type, mean age and gender before (1958-1972) (I) and after (1985-2003) (II) salt iodization in the province of Salta, Argentina. 

Promote actively and worldwide all policies leading to universal salt iodization. 

Utilization of iodized table salt, together with its use in processed food should theoretically provide for dietary requirements. Except in countries who have adopted a policy of universal salt iodization (USI) the availability and... 

This program has refied on the use of iodized salt through a policy known as universal salt iodization (USI). This requires all salt for human and animal consumption to be iodized at a level of 20—40 mg iodine/kg potassium iodate. 

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