The thyroid gland is one of the largest endocrine glands: in an adult it weighs 15-20 g and consists of two lobes 4 cm long and 2-2.5 cm wide, connected by an isthmus. It owes its name to the anatomical proximity to the laryngeal cartilage, which outlines resembles a shield. Sometimes the thyroid gland can be located not behind the cartilage, but, for example, in the root of the tongue or behind the sternum. In some people, it is completely absent. If earlier babies born without a thyroid gland were doomed, now synthetic hormonal drugs fully compensate for the lack of natural thyroid hormones in the blood.
The purpose of the gland is to produce thyroid hormones: thyroxin and triiodothyronine. Iodine is absolutely necessary for the normal functioning of the thyroid gland, since it is part of the hormones: thyroxin contains four iodine atoms, and triiodothyronine – two. The body can not synthesize iodine on its own, we get it exclusively with food.
What happens if iodine in the diet is not enough? In order to capture more iodine, the thyroid gland begins to grow – the number and volume of thyroid cells increase – a goiter is formed. So the body compensates for iodine deficiency. But if iodine deficiency persists long enough, an increase in the gland volume does not normalize iodine intake and iodine deficiency symptoms appear.
Thyroid hormones regulate the growth and development of cells, functions of the central and peripheral nervous systems, muscular, reproductive, bone, cardiovascular, respiratory and other systems of the body. And most importantly, they can control the processes of protein synthesis. Another very important effect of thyroid hormone action is the ability to stimulate cell and tissue respiration in mitochondria. Therefore, iodine deficiency leads to serious consequences: mental abilities decrease, apathy and drowsiness appear, and metabolism is disturbed.
Over a lifetime, a person consumes only 3-5 g of iodine. Iodine as a trace element is part of many natural organic compounds or is present in inorganic salts in the form of iodide anion. 10-20% of the total amount of iodine ingested into the body selectively absorbs the thyroid gland, in which 6000-8000 mcg is usually concentrated. In the blood, 500-600 mcg of iodine circulates. Every day, the thyroid gland consumes 75 micrograms of iodine for the needs of the body. The daily need of the whole body is 100-200 mcg of iodine, depending on age and health. Doctors endocrinologists recommend the following rates of iodine intake:
children from 2 to 6 years old – 90 mcg;
children from 7 to 12 years old – 120 mcg;
adults 12 years and older – 150 mcg;
pregnant and lactating women – 200 mcg.
Thus, the largest amount of iodine is required for pregnant women. This is not surprising: thyroid hormones are necessary for the development of the fetus. The thyroid gland of the fetus begins to work from the 12th week of pregnancy, so the first three months the embryo develops exclusively due to the mother’s thyroid hormones. If there are not enough of them, the whole body of the unborn child suffers, and above all his brain. In addition, iodine deficiency is dangerous for the mother, since the body’s iodine intake increases during pregnancy. So, the lack of it in the food of a pregnant woman can lead to the rapid development of goiter.
Almost the entire population with the exception of the inhabitants of the sea coasts, lives in areas with a slight, moderate and severe natural iodine deficiency. But this is not the only reason for the development of thyroid diseases. Vegetables belonging to the cruciferous family contain organic compounds with a SCN group: thiocyanates and isothiocyanates. This family includes white cabbage, Brussels and cauliflower, broccoli, turnip, horseradish, watercress. It is proved that thiocyanates and isothiocyanates are goiter-promoting substances. Another group of food goiter consists of products containing substances that are precursors of thiocyanates. These include cassava, corn, sweet potatoes, beans, maize. Coal, shale, domestic and industrial waste, chemical fertilizers and pesticides have goitogenic properties. Thiocyanates are also found in tobacco. All these products disrupt the synthesis of thyroid hormones, aggravating the natural iodine deficiency.
To compensate for the lack of iodine in different ways. The most effective and economical method is iodization of table salt and bread. This method of prevention is called “dumb”: a person often does not know that he eats a food product enriched with iodine. Currently, a new standard has been adopted in Russia, which involves the addition of 40 ± 15 mg iodine per kilogram to table salt. The use of iodized salt in many cases can eliminate iodine deficiency. However, at certain periods of life (children and adolescents, pregnancy, breast-feeding), the body needs regular additional intake of physiological doses of iodine. In such cases, prescribed drugs containing a physiological dose of potassium iodide, for example, Iodomarin, one tablet of which contains a daily dose of iodine.
Is it possible to normalize the level of iodine in another way? Of course, if you eat oysters, sea pap, squid, sea kale and scallops every day, as the Japanese do. They consume up to 1,500 micrograms of iodine per day and do not suffer from goiter. In our own conditions, it is most advisable to regularly use iodized salt, as the Austrians, Swiss, French, living in conditions of severe natural iodine deficiency, and take Yodomarin.