Iodine iodized salt prophylaxis

Iodized salt prophylaxis. Goiter is endemic in regions where soils are deficient in iodine. Use of iodized table salt allows iodine requirements (150-300 pg/d) to be met and effectively prevents goiter. 

Qinghai Province lies on the Tibetan plateau and has a population of 4 million comprising Han Chinese, Tibetans and the Wee people. The majority of the population relies on subsistence agriculture for their livelihood and the area is severely iodine deficient. The prevalence of cretinism has been estimated as exceeding 10% by the Ministry of Public Health. Iodized salt prophylaxis was introduced in 1978 and the cretin rate has fallen greatly since then, particularly in the eastern counties of the Province. 

THE EFFECTS OF IODIZED OIL AND IODIZED SALT PROPHYLAXIS ON COGNITIVE FUNCTIONING IN IODINE DEFICIENT ENDEMIAS IN CHINA... 

A lot of epidemiological data also fit well into the assumption that there is some age dependency of the iodine utilization by the thyroid. 13 years after the onset of iodized salt prophylaxy in Austria, the incidence of "school goiter diminished from 31% to 4%. In contrast, 31,8% of the adult women and 13% of men still had goiters at this time (62). A similar "dying out" of non-toxic goiter occurred in Switzerland (22). One has to admit, however, that only the preventive effect on goiter development has been ascertained by these studies. 

The daily requirement for iodine in adults is 1-2 /ag/kg body weight. In the U.S., recommended daily allowances for iodine range from 40 to 120 /xg for children, 150 fxg for adults, 220 fxg for pregnancy, and 270 p,g for lactation. Dairy products and fish have relatively high iodine contents. Because of concerns of iodine insufficiency, iodine supplementation has been widely used for prophylaxis and therapy. The most practical form of this supplementation has been addition of iodide or iodate (now preferred) to table salt. In the U.S., such supplementation is optional and iodized salt provides 100 fxg of iodine/g. 

Possible dietary sources of iodine for vegans include iodized salt and seaweed (Lightowler and Davies, 1996). In many developing countries, iodized salt is considered a good medium for iodine prophylaxis. However, although some iodized salt contains 1527-25 57 fig/lOOg (equivalent to 76-128 pg/teaspoon), encouragement to use this... 

The possible consequences in terms of iodine loss from the increased UI excretion in different study populations have been investigated in Ireland and the UK, areas of borderline dietary iodine intake. Data have been compared to the values obtained from Sri Lanka, in which a program of iodine prophylaxis via iodized salt has been in operation for some years, and are shown in Table 49.5 (Smyth, 1999). 

Effects of silent iodine prophylaxis and iodized salt implementation programs in pregnant women... 

Active prophylaxis (AP) is the provision of iodine supplements to an iodine-deficient population. Beside the individual supplementation of oral iodine and injections of iodized oil, the most common supplementation strategy is the iodization of salt, water and animal feed. Some countries allow only iodized salt to be sold, while other countries allow both iodized and uniodized salt. 

The presence of goiter in Italy has been known since the ancient Roman Age. In recent years, several surveys have shown high rates of the prevalence of goiter and low urinary iodine excretion. Active prophylaxis has been very hmited (Aghini-Lombardi et ai, 1998). Before 2005, prophylaxis with iodized salt in the country was performed on a voluntary basis. For this reason, iodized salt consumption in Italy still accounted for approximately 3%... 

Iodine is essential for normal growth, since it is a requisite part of the thyroid hormone. In cretinism, or congenital hypothyroidism, which is observed in goitrogenous areas, growth may be stimulated by administration of dessicated thyroid. Iodine also plays a role in human and animal fertility and in lactation. Simple goiter and cretinism are still prevalent in many areas of the world prophylaxis could be obtained through the universal use of iodized salt. 

Iodized salt has been the major prophylactic measure for iodine deficiency worldwide. In some industrialized countries such as Switzerland, Finland, and Austria, iodized salt has been the mainstay of iodine prophylaxis. In others, its use is optional for example, about half of the salt sold in the United States in 1970 was reported to be iodized. The amount of iodine ingested in salt depends on the level of fortification, iodine retention in salt, and the amount of salt consumed. Switzerland has gradually raised the iodine content of its salt as daily salt consumption decreased over the decades (9). 

Iodized salt was introduced already in the late 40 s but still in the 50 s the iodine intake was only 50-70 ug/d of which only 15 ug derived from the salt. Endemic goitre was found all over the country but the most heavily affected areas were located in the inland and particular ly in the east. Goitre was abundant in newborns and occurred up to 30% in school children. Since the early 60 s table salt contains 25 mg Kl/kg and since the late 60 s the use of iodized salt is >90 % of the total consumption. Goitre has been common also in domestic animals and prophylaxis was practized during many decades but in the 70 s it was intensified. In consequence, the mean iodine intake in the population rose to about 300 ug/day or more at the end of the 70 s. ... 

Local and transient iodine prophylaxis programs have been implemented in local scale over the past 30 and 40 years. The manifacture of iodized salt was allowed by law in 1972 and distributed on request to selected endemic areas. In 1977 the distribution was extended to the whole Country. In 1991 the amount of iodine has been raised from 15 to 30 mg/kg of salt by a Public Ministry Decree and potassium iodate in addition or substitution of potassium iodide has been allowed. 

So far a satisfactory iodine prophylaxis on a relatively high scale has been achieved only in Provincia Autonoma di Bolzano (Alto Adige), where more dian 50% of the population uses iodized salt and the prevalence of goiter ws abated from 22.2% to 2.4%. At smaller scale, a succesfiill program of iodine prophylaxis has been obtained in an endemic area of Toscana where a survey carried out in 1991, ten years after the initial observation prior to the local introduction of iodized salt, has documented in schoolchildren a reduction of die prevalence of goiter from 60% to 9% and an increase of mean urinary iodine excretion from 47 22 to 130 73 pg/g of creatinine 13. 

In conclusion, iodine supplementation in Eastern Germany was never satisfactory but has worsened since 1989. At least in Greifswald, the iodine intake is as low as the level before prophylaxis was started. That finding coincides with decreases in consumption of iodized salt (84 % to 20 %) and in the use of iodized mineral mixtures in animal feeding. Clearly, public education about the importance of iodine prophylaxis should be intensified. 

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. 

In 1991 the Polish Council for Control of Iodine Deficiency Disorders within the Polish Society of Endocrinology as an advisory body of the Ministry of Health has been created. In January 1997 the Minister of Health put in operation a mandatory model of household salt iodization, with 30 10 mg Kl/kg of salt (Szybinski, 1998). This meant that all kitchen salt was iodized, and noniodized salt was not available on the market. However, in food production and food processing, noniodized salt has to be, and is, used. The history of iodine prophylaxis in Poland is shown in Table 83.1 (Szybinski, 1998). 

Voluntary model of iodine prophylaxis (household salt iodization 20 10 mg Kl/kg of salt)... 

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