Scientific iodine supplementation: preventing deficiency has many benefits

my country is a country with serious iodine deficiency, with about 720 million people living in iodine-deficient areas. The region is wide and the population is large, especially for newlywed women of childbearing age, pregnant women, infants and young children. However, in real life, people lack knowledge about the hazards and prevention of iodine deficiency (IDD).

Understanding Iodine Deficiency Disorders

Iodine deficiency disease is a general term for a group of related diseases caused by iodine malnutrition in the body due to iodine deficiency in the natural environment. It includes endemic goiter, cretinism (cretinism is a type of cretinism caused by thyroid hypofunction in children, which can be divided into endemic cretinism and sporadic cretinism) and sub-cretinism, simple deaf-muteness, fetal abortion, premature birth, stillbirth and congenital malformations. It is essentially a micronutrient malnutrition, and is listed as one of the three major micronutrient malnutrition diseases that are focused on prevention and treatment and eliminated within a time limit by international organizations such as the World Health Organization and the United Nations Children's Fund, along with vitamin A deficiency and iron deficiency anemia. Iodine deficiency disease mainly occurs in specific iodine-deficient geographical environments, has obvious local characteristics, and is listed as one of the endemic diseases in my country.

The iodine content of most terrestrial plants is low, with an average of no more than 1.0 mg per kilogram. Only spinach and celery have higher iodine content, reaching 1.64 mg and 1.60 mg per kilogram.

The iodine content in seafood is several times or even dozens of times that of land plants. For example, the iodine content of kelp is 10 mg per kilogram. Marine fish and seaweed are also good foods for daily iodine supplementation. Eating kelp regularly can not only supplement iodine in the body, but also ingest other trace elements, amino acids and vitamins. Therefore, seafood is the best natural iodine supplement product.

The most obvious effect of iodine deficiency on adults is goiter. The characteristic of endemic goiter in adults is the lack of typical clinical symptoms of hypothyroidism. Except for the swelling of the neck, there are generally no obvious symptoms. Only when the goiter develops to a certain extent or compresses the trachea, esophagus and peripheral nerves will symptoms such as dyspnea, dysphagia or hoarseness appear. Although most people have no obvious clinical manifestations, laboratory tests often find that the patient's thyroid hormone levels are low, and a small number of people may have mild symptoms of hypothyroidism. These people often show indifference, weakness, fatigue, decreased physical fitness and poor ability to adapt to life.

Iodine deficiency in pregnant women not only affects their own health, but also easily causes stillbirth, spontaneous abortion and premature birth, and can also cause congenital malformations, simple deaf-muteness, etc. More importantly, it can cause irreversible damage to the development of the brain, with severe cases causing stupidity, dwarfism, deaf-muteness, paralysis, and mild cases causing mental retardation, which affects learning.

Children and adolescents are more sensitive to iodine deficiency, and the most prominent manifestation is thyroid enlargement. Generally speaking, the rate of thyroid enlargement increases with age, and the enlargement rate of girls is generally higher than that of boys. After a certain period of iodine supplementation, it can return to normal. Iodine deficiency in children and adolescents can cause damage to growth and development, especially intellectual development. Children in iodine-deficient areas often do not reach the expected level of intellectual development. If expressed in terms of intelligence quotient, iodine deficiency can cause children's intelligence quotient to lose 10 to 15 percentage points.

Infants and young children are in the second critical period of brain development. Like fetuses, they are extremely sensitive to iodine deficiency. If severe iodine deficiency in fetuses continues into infancy, they will inevitably develop into typical cretinism patients. If the degree of iodine deficiency in young children is relatively mild, they may have mild mental retardation. In infancy, it only manifests as delayed reactions to people and things around them, as well as delayed motor skills, intelligence, and growth and development.

The main hazard of iodine deficiency in newborns is the increase in the detection rate of congenital hypothyroidism (congenital hypothyroidism). In developed countries with normal iodine nutrition, the detection rate of congenital hypothyroidism is generally 1/3,500 to 1/5,000. In developing countries with iodine deficiency, the detection rate can be as high as 5% to 10%, which means it has increased by 200 to 500 times. If congenital hypothyroidism is not diagnosed and treated early, it will also lead to lifelong intellectual disability in children.

Iodine is one of the essential trace elements in human life activities and exists in the form of iodide in human blood. A normal adult only needs to obtain about 100 micrograms of iodine from the outside world every day. When the human body lives in an iodine-deficient environment for a long time and the daily iodine intake is less than 50 micrograms, it may suffer from iodine deficiency.

Why does iodine deficiency cause disease?

In the front and lower part of the human larynx, there is a gland divided into two lobes, the thyroid gland. Like the pituitary gland and adrenal gland, it is an endocrine gland that secretes a hormone called thyroxine. Although the amount of thyroxine is very small, it plays an extremely important role in the metabolism, growth, and development of the human body. It can increase the oxygen consumption of most tissue cells in the human body and increase heat production to maintain basal metabolism. Thyroid hormones can also promote the body's absorption and utilization of sugar and regulate the synthesis and decomposition of fat in the human body.

Thyroid hormone promotes the growth and development of infants and young children by promoting cell division and strengthening the synthesis of DNA in cells. It helps growth hormone to work. Without it, the growth-promoting effect of growth hormone cannot work well. Thyroid hormone is particularly important for the central nervous system and bone development of infants and young children. Insufficient thyroid hormone not only makes infants and young children short in stature, but also makes their brains underdeveloped and mentally retarded, which is called "cretinism". Children with this disease cannot fully mature their nasal bones and orbital bones, resulting in special facial features such as collapsed noses, widened distance between the eyes, thick lips, and large tongues.

It can be seen that thyroid hormone plays a vital role in human growth and development, and the production of thyroid hormone must use thyroglobulin and iodine as raw materials. Thyroglobulin is synthesized by the thyroid gland itself, and iodine must be obtained from food. Once people get less iodine from food, the thyroid "processing plant" will "reduce production" due to insufficient "raw materials", resulting in a decrease in thyroid hormone in the human body. This is the cause of iodine deficiency.

Of course, the amount of iodine the human body consumes is not the more the better. When the body's iodine intake exceeds the normal physiological requirements for a long time, it can also cause goiter and even diseases such as hyperthyroidism.

The most fundamental measure to prevent and treat iodine deficiency is to eat iodized salt. This is the best method among various iodine supplementation methods. It is not only safe, effective, economical and easy to promote, but also meets the requirements of trace, long-term and daily life. However, iodine is a very active substance. The iodine in salt will be lost as the storage time increases, resulting in less and less iodine content. Therefore, pay attention to the following matters when using it.

1. Pay attention to the storage method of iodized salt. Put iodized salt in a glass or ceramic jar with a lid, and place the jar in a cool place without direct sunlight. Try not to heat the salt. When stored in a high temperature environment, iodine is lost faster than when stored in a low room temperature environment. In addition, do not buy too much salt at one time, otherwise you will buy iodized salt but not eat iodine.

2. Pay attention to the cooking method. Adding salt first when cooking will cause the iodine to evaporate when heated. Therefore, try to add salt later when cooking, and do not add iodized salt to hot oil and fry it together with the food.

3. Pay attention to the amount of salt you eat. According to my country's iodized salt standards, each person can obtain about 120 micrograms of iodine by eating 6 grams of salt per day, which can fully meet the physiological needs of most adults. Pregnant women, breastfeeding women, infants and young children and other special groups need more iodine than ordinary people. Therefore, pregnant women, breastfeeding women, infants and young children and other special groups should take iodized oil pills or eat seafood frequently, so that they can eat less salt and supplement appropriate iodine.

A very small number of people, such as those with hyperthyroidism and thyroid inflammation, should not consume iodized salt. Residents living in high-iodine areas, who already get a high dose of iodine from high-iodine food and drinking water every day, may develop high-iodine goiter, so these people should not consume iodized salt either.