Iodine deficiency seriously harms human health. The main manifestations of iodine deficiency are: damage to the development of children's brains and nerves, manifested in different degrees of mental retardation and poor learning ability. Endemic goiter, commonly known as thick neck root or big neck disease; Severe iodine deficiency can lead to endemic cretinism. It is deaf, dumb, dull and stupid. It leads to the death, deformity, deafness or miscarriage and premature birth of the fetus growing in the mother's stomach. Adult's physical strength and labor ability decline, and children's growth and development are affected. In addition, iodine deficiency significantly affects the growth, reproduction and productivity of livestock, reducing the output and quality of meat, eggs and milk. Scientists have found that women are more prone to iodine deficiency than men. Children and adolescents grow and develop faster, and their bodies need more iodine. Adolescent girls and pregnant women need iodine more for physiological reasons, so they are very sensitive to iodine deficiency, iodine deficiency and iodine deficiency disorders.

Iodine deficiency and its causes

We know that food is the main source of iodine in the body. If the soil in our living environment contains less iodine, so do the plants growing on this soil, and all kinds of animals (such as sheep, cattle, dogs and rabbits) who eat low-iodine feed will also suffer from iodine deficiency. Therefore, the iodine nutritional status of the body is closely related to the environment. If you eat food and meat with low iodine content for a long time, iodine deficiency will occur, and your body will be affected to some extent, and everyone, especially children and women, will not be spared. Although most people seem to be "normal", only some people will have obvious lesions-endemic goiter and endemic cretinism. But in fact, this "normality" is a hidden pathological state. Scientists say that iodine deficiency disorder (IDD) is one of the oldest diseases in human beings, and it is all the adverse effects (pathology) caused by iodine deficiency on human physical and intellectual development. In the 7th century BC, there were written records in China, saying that people should be ill. Ge Hong of Jin Dynasty first proposed to treat endemic goiter (an iodine deficiency) with seaweed and kelp. It was not until the 20th century that people generally realized that iodine could be used to prevent iodine deficiency disorders and achieved success. Iodine is one of the essential trace elements for human body. The total amount of iodine in healthy adults is 30 mg (20 ~ 50 mg), of which 70%~80% exists in the thyroid gland.

Physiological functions of iodine:

1. Promote biological oxidation: Thyroxine can promote biological oxidation in the tricarboxylic acid cycle, coordinate the coupling of biological oxidation and phosphorylation, and regulate energy conversion.

2. Regulate the synthesis and decomposition of protein: when protein is insufficient, thyroxine can promote the synthesis of protein; When protein is ingested sufficiently, thyroxine can promote the decomposition of protein.

3. Promote the metabolism of sugar and fat: Thyroxine can accelerate the absorption and utilization of sugar, promote the decomposition and oxidation of glycogen and fat, and regulate the concentration of serum cholesterol and phospholipids.

4. Regulating water and salt metabolism: Thyroxine can promote water and salt in tissues to enter the blood and be discharged from the kidneys. When it is deficient, it can cause water and salt retention in tissues, and interstitial fluid containing a large amount of mucin appears in tissues, resulting in mucinous edema.

5. Promote the absorption and utilization of vitamins: Thyroxine can promote the absorption and utilization of nicotinic acid, the process of transforming carotene into vitamin A and the process of synthesizing riboflavin adenine dinucleotide from riboflavin.

6. Enhance enzyme activity: Thyroxine can activate many enzymes in vivo, such as cytochrome, succinate oxidase, alkaline phosphatase, etc. , and play a role in substance metabolism.

7. Promote growth and development: Thyroxine promotes bone development and protein synthesis, and maintains the normal structure of the central nervous system.

It is worth noting that too much iodine intake is also harmful to human body, and too much iodine intake in daily diet can also cause hyperthyroidism. Whether it is necessary to "supplement iodine" in addition to the normal diet, we must have regular physical examinations and follow the doctor's advice, and we must not blindly "supplement iodine". During the Quaternary Glacier Period, due to the change of the earth's natural environment, glaciers melted, floods flooded, and a large number of raindrops washed repeatedly, bringing almost all iodine into the surface rocks and mature soil on land.