Iodine is one of the essential trace elements, known as intellectual nutrients. People in life, but a few grams of iodine requirement, but this is but a few grams of iodine plays exceptionally important role in the human life cycle, it promotes the formation of life, and guide the development of life.
[Why iodized salt]
Iodine intake is not enough time, insufficient thyroid hormone synthesis, thyroid unfavorable, can cause iodine deficiency disorders, such as iodine deficiency in pregnant women cause fetal mental retardation, physical barrier, the barrier of adolescent boys and girls because of the need iodine or increase dietary intake of iodine deficiency, which leads to the well-known large neck disease that is goiter and the like.
Also cause thyroid and health hazards, such as goiter, hyperthyroidism, thyroiditis and other thyroid-related diseases when excessive iodine intake. In fact, the relationship between iodine intake and thyroid disease presents a U-shaped intake is too low or too high will lead to an increase in thyroid disease.
My country is one of the hardest hit by iodine deficiency diseases in the world, according to 1990 statistics, there are 1.1 billion people worldwide iodine deficiency, China accounted for 440 million, in addition to Shanghai, China has 29 provinces, municipalities and autonomous regions there is iodine deficiency disorders. Thus, in 1992, China pledged the United Nations World Conference on Nutrition: the improvement of the national variety dystrophy, one of which is an important measure of universal salt iodization. In this way our country to solve the Chinese people's iodine malnutrition, iodine deficiency problem, which is not visible on the pharmaceutical market iodine supplement health food, supplements reasons.
With the significant increase in the national population iodine intake, iodine deficiency disorders in most parts of the situation has been significantly improved. Iodine deficiency disease nationwide monitoring results showed that: At present, there are 27 provinces reached eliminate or substantially eliminate iodine deficiency situation. But China's vast territory, the environment, diet and lifestyle differences, around the "iodine feeling" very complicated, in some areas of high iodine, iodine deficiency, iodine regional mixed proper existence. In the salt intake should be different in different parts of the policy, in July 2010, Weisheng Bu announced "edible salt iodine content," the announcement, it is necessary to make an appropriate reduction in the iodine content of iodized salt announcements from 20 to 60 mg / kg down to 20 to 30 mg / kg.
[Source of iodine and the supply amount]
Due to the high incidence of thyroid disease coastal cities, some experts believe, is to eat seafood high iodine induced thyroid disease high. In fact, some experts later calculated, mostly seafood products containing iodine in 10 micrograms / 100 g or less, eg: shrimp 8.4, 9.5 small yellow croaker, pomfret 8.9, 8.7 octopus, crab 8.4, 4.7 fish plate, but dried seaweed and seaweed is particularly high, respectively, 17,500 and 245 (units are in g / 100 g). If you eat 500 grams of seafood a day only about 50 micrograms of iodine intake, and eat 10 grams salt per day, the intake of more than 350 micrograms of iodine, iodized salt iodine is greatly higher than seafood.
At present, the body needs iodine mainly from salt, about 80% to 90% of the total daily secondly, from drinking water and food. Strengthening of potassium iodate salt is used in our interventions, if according to eat 10 grams of salt per person per day is calculated, then a person per day of salt intake from 10 grams to 200 micrograms of iodine (normal is 150 to 800 micrograms / day), a safe range from the normal supply of iodine to the risk of poisoning amount is large, and therefore in the national consumption of iodized salt today, the daily intake of iodine in the human body is basically safe.
[Iodized salt will lead to thyroid cancer]
Through epidemiological survey, some scholars believe that the long-term excessive intake of iodine can increase the incidence of thyroid cancer, there may be some relationship between the two. Because, with the body in a sufficient amount of iodine or iodized salt periodate state continues supplement iodine intake after 1999, does have some problems, the population living in iodine area of about 30.98 million domestic Some coastal provinces of Liaoning, Zhejiang, Fujian, Shanghai and other thyroid diseases on the rise, this phenomenon is considered an excess of Hebei Huanghua port manifold rural areas of high iodine, thyroid cancer prevalence was significantly higher than the average prevalence countries.
Foreign countries also have similar reports in Australia since 1963 after the implementation of universal salt iodization, thyroid cancer incidence rate 3.07 / 100,000 yearly rise was 7.8 / 100,000, the researchers believe that the prevalence of thyroid cancer increased iodine intake and increase may have a certain relationship. US scientists in Hawaii and Ireland iodine area, thyroid cancer case-control study carried out by quantitative determination of iodine intake of seafood found that excessive iodine intake of people with subclinical thyroid dysfunction in women is a risk factor one. Foreign reports agree that, regardless of normal iodine iodine area or region, women, especially young women in the reproductive period, the incidence of thyroid cancer increased significantly in recent years, and far higher than men.
Thyroid cancer is a relatively common malignancy, from a global perspective, the most recent years, including thyroid cancer, including tumor were tested rise. With the improvement of medical standards, extensive use of modern equipment, technologies, such as blinking developing thyroid, ultrasound and fine-needle biopsy of thyroid cancer greatly improves the detection rate. In addition, the pathogenesis of thyroid cancer is not clear so far, many risk factors, genetic, autoimmune, smoking, drinking, mental health, social and psychological factors are related. Therefore, the simple study on the incidence of thyroid cancer is not enough iodized salt from a factor, also taking into account factors such as the impact Huanjingwuran thyroid cancer incidence.
Many studies have shown that the incidence of thyroid cancer in women was significantly higher than males, and female hormone levels. Women during menstruation, pregnancy, lactation period, the body increases and cyclical changes was important virulence factors thyroxine requirements.
On the contrary, more consistent view is that, with the onset of periodate not all thyroid tumors. In some cases, iodine causes thyroid cancer type is changed, the intervention can take iodine to low thyroid cancer malignant transformation. Control of Iodine Deficiency Disorders 2009 International Council also announced that the benefits far outweigh the risk of iodine overdose of World Health Organization (WHO) believes that there is no clear scientific evidence that iodized salt or iodine excessive intake of thyroid tumors are directly related.
In short, continued to maintain iodine nutritional status is necessary in a safe range for improving the quality of life have a decisive role. Most European countries, residents may voluntarily choose whether consumption of iodized salt, Denmark and other countries legislation prohibiting residents consumption of iodized salt, only eight countries to implement iodized salt. So far, 32 European countries belonging to iodine deficient areas, but only 27% of the residents consumption of iodized salt.
In 2005, the state stopped the supply of iodized salt in iodine area principle. However, the difficulties in the country to buy iodized salt remains. The past, people only with a medical certificate to buy non-iodized salt in the salt stores. August 2010, non-iodized salt entered Beijing 19 supermarkets. In addition, Shanghai, Zhejiang, Shandong and other provinces also increased non-iodized salt sales outlets. Recently, non-iodized salt began to broad access to supermarket sales, and does not require any proof.
(From: "encyclopedic knowledge" Zhang Yin Hong)
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