【Prevention and treatment of iodine deficiency disease】Do thyroid diseases still need iodine supplementation? Iodine supplementation suggestions for different populations!

Today (May 15, 2024) is:

The 31st National Iodine Deficiency Prevention and Control Day

The theme of this year's event is:

"Salt iodization to prevent diseases, balanced nutrition and health"

Iodine is an important trace element that affects mental development, and iodine deficiency in the human body will cause varying degrees of damage, leading to iodine deficiency diseases and even disabilities. However, in real life, people lack knowledge about the dangers of iodine deficiency and its prevention. In this regard, in view of some problems and confusions of the public in the prevention and control of iodine deficiency in salt iodization, national endemic disease prevention and control experts have carried out popular science interpretation.

The dangers of iodine deficiency need to be understood

Iodine deficiency diseases are a group of harmful diseases induced by iodine malnutrition caused by iodine deficiency in the natural environment, including endemic goiter, endemic cretinism, endemic subclinical cretinism, and miscarriage, premature birth, stillbirth, congenital malformations caused by iodine deficiency.

Among them, endemic goiter and endemic cretinism are the most common and severe manifestations, respectively. "Stupid, small, deaf, dumb, and paralyzed" are the most significant characteristics of endemic cretinism. School-age children born and living in iodine-deficient areas have varying degrees of intellectual impairment, and their IQ levels are significantly lower than those of children in iodine-deficient areas. Iodine deficiency in fetuses and infants interferes with brain development, resulting in a serious "landslide" of intelligence, which is manifested as the gradual development characteristics of "one generation A, two generations of stupidity, three generations and four generations of broken roots".

A global strategy for iodine supplementation

At present, the most commonly used iodine supplementation methods are salt iodization, and other means include oral iodized oil pills, iodine-containing drugs and nutrient supplements, and consumption of iodine-rich foods.

Salt iodization is a safe, effective, sustainable, convenient, economical and daily iodine supplementation measure. In order to prevent and control iodine deficiency diseases, international organizations such as the World Health Organization and the Global Alliance for Iodine Nutrition have implemented a universal salt iodization strategy around the world. In addition to salt iodization, iodine-rich foods can also be supplemented with iodine. Different foods have different iodine content, and some seafood products have higher iodine content, such as kelp, seaweed, hairtail, dried scallops, etc.; Among other foods, eggs contain higher iodine; The iodine content of different milk types varies greatly; Plants have the lowest iodine content, especially fruits and vegetables.

When choosing iodine supplementation, you can first consider supplementing with iodine through iodized salt and iodine-rich foods such as kelp and seaweed. In addition to this, iodine-containing supplements may also be considered. The dose of iodine supplementation is selected according to the degree of iodine deficiency. In areas with severe iodine deficiency, iodized oil pills can be given to women of childbearing age, pregnant women and lactating women when iodized salt prevention and control measures cannot be effectively implemented. Oral iodized oil pills and iodine-containing drugs are group iodine supplementation measures.

The study shows that the iodine content of fish, poultry, egg products, pickled and animal foods is relatively high in prepackaged foods in mainland China, and nearly 90% of all prepackaged foods use iodized salt, indicating that the use rate of iodized salt in prepackaged foods in mainland China is relatively high. In addition, some condiments also contain iodine, but the iodine content varies greatly due to different types and brands, and the higher iodine content is fish sauce, spices, chicken essence and sauces.

Iodine supplementation recommendations for different populations

1. The general population The vast majority of the mainland is an iodine-deficient area, and the iodine obtained by the general population from food and drinking water every day cannot meet the normal needs, and additional iodine supplementation is required; Except for residents who live in areas with high iodine in water sources or who have some kind of thyroid disease and do not consume iodized salt as prescribed by their doctors, everyone else should consume iodized salt. At present, the salt intake of mainland residents is on a downward trend, and "Healthy China" has also put forward a salt reduction target. At the same time, the number of dining out and take-out forms has increased, and the variety of food has become richer and more diverse than before, which has changed the traditional situation of relying on salt and iodine at home. Therefore, the mainland is also actively adjusting the iodine content of table salt to ensure that the iodine nutrition of the population is appropriate.

2. Special needs of the population pregnant women, lactating women, infants and young children (after birth to 36 months of age) and other groups are the special needs of iodine, children and adolescents are the key groups for the prevention and treatment of iodine deficiency diseases, in daily life this part of the population should pay special attention to adequate iodine supplementation. Taking pregnant women as an example, in the stage of preparing for pregnancy, iodized salt should be consumed in order to achieve good iodine nutritional status; After pregnancy, pregnant women should choose iodized salt or iodized salt with high iodine content, and encourage the intake of iodine-rich seafood such as kelp and seaweed.

3. Infants and young children from birth to 36 months of age are the critical period of infant growth and development, and sufficient thyroid hormone is needed to promote physical growth and nervous system development. Breastfed infants and young children can meet the needs of infants aged 0~6 months when the mother's iodine intake is sufficient; Infants aged 7~12 months can obtain some iodine from complementary food; Children aged 13~24 months begin to try adult food, and they will also consume a small amount of iodized salt, which can obtain a certain amount of iodine. Iodine-containing seafood should be included in the complementary food for infants and young children. Non-breastfed infants and young children are mainly fed dairy products, and infant formula must be iodized.

Iodine supplementation in special areas is particular

1. Water-sourced areas with high iodine Residents living in water-source areas with high iodine have consumed sufficient or even excessive iodine from drinking water, so these residents should consume uniodized salt; However, if the iodine content in the water drops to the level of iodine deficiency and residents are unable to consume enough iodine from drinking water, it is necessary to consume iodized salt if the water content drops to the iodine deficiency level.

2. Coastal areas Although iodine-rich foods such as kelp and seaweed are abundant in coastal areas, if the local residents eat less frequently and consume less iodized salt, most of their residents' iodine intake will be lower than the recommended intake of international organizations and the mainland, and the risk of iodine deficiency is very high.

How to supplement iodine for thyroid disease

1. For patients with hyperthyroidism, iodine intake should be restricted, and iodine-rich foods and drugs should be avoided. If radioactive iodine is needed to treat hyperthyroidism, foods that contain a lot of iodine, such as seaweed, should be fasted for at least 7 days. However, if the thyroid gland is completely removed or completely destroyed due to hypothyroidism, the patient needs to receive thyroid hormone replacement therapy, so the consumption of iodized salt or non-iodized salt has no significant effect on the thyroid gland. If thyroid lobectomy or thyroid tissue remains, a normal iodine diet can be used, including iodized salt.

2. For patients with thyroid nodules, excessive or insufficient iodine intake can increase the prevalence of nodules, so it is necessary to have an appropriate iodine diet. In recent years, although the incidence of thyroid cancer has increased significantly, no correlation between iodine supplementation and the increased incidence of thyroid cancer has been found, so patients with thyroid cancer can receive an iodine diet normally.

At the same time, in order to ensure the needs of the mother and the fetus, women with thyroid disease during pregnancy should also consume enough iodine, and eating iodized salt is the best way. Patients with pre-pregnancy hyperthyroidism and a low-iodine diet should consume iodized salt at least 3 months before the intended pregnancy to ensure adequate iodine stores during pregnancy. Patients with hyperthyroidism during pregnancy should also take adequate iodine, monitor thyroid function regularly, and adjust the dose of antithyroid drugs in a timely manner.

Supervising expert: Professor Liu Peng, Institute of Iodine Deficiency Disease Prevention and Control, Endemic Disease Control Center, Chinese Center for Disease Control and Prevention

Su Xiaohui, researcher at the Center for Endemic Disease Control of the Chinese Center for Disease Control and Prevention

Correspondent: Yi Xiaofeng

Editor: Yu Jiaxing

Reviewer: Chen Shirui

Issued: Daley Red

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