As we all know, many chemical elements in geochemistry are harmful to human body, and some are beneficial to human body. But all chemical elements beneficial to human body are double-edged swords, so: less will cause disease, and more will cause disease. Here we can draw a conclusion that the secret of nature to human health care is a word "degree".

Modern science has found that the human body needs to contain more than 60 kinds of chemical elements, among which 1 1 elements such as oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, chlorine and magnesium account for 99.9% of the human body's weight, which is called "macro" elements in academic circles. The rest, less than 0. 1%, is composed of four elements, such as silicon, iron, fluorine, zinc, iodine, copper, vanadium, manganese, nickel, selenium, chromium, tin and molybdenum, which are called "trace" elements in academic circles. There are more than 30 kinds of trace elements in human body, which can only be shown as "trace" in laboratory testing. Some of these elements are necessary for special physiological functions of human body, while others are toxic to human body, such as lead, cadmium, mercury, hexavalent chromium and arsenic.

When all these elements exist in the human body to the required extent, the human body will be healthy. However, in the process of metabolism and physical activity, due to the constraints of geochemical environment and artificial eating habits, when the intake of a certain element is too much or too little, it will show some discomfort in the human body, and even get sick to varying degrees.

At present, people are very concerned about the influence of macro element sodium on human body. Sodium is widely distributed on the earth, mostly in various rocks in the form of "sodium oxide". The sodium needed by human body is "sodium chloride", that is, "salt". Rice, oil and salt are four indispensable necessities for people. Some people like salty food (heavy taste), while others like light taste (light taste). There is knowledge here, which should not be underestimated. Because sodium is an essential mineral nutrient for human metabolism, it plays a certain role in maintaining the balance of cell pH and maintaining the normal movement of nerves, muscles, heart, kidneys and various physiological functions of the human body. After sodium is ingested, it will be metabolized to the outside world through urine, feces, sweat, tears and snot. And excreted mainly through sweat. If the intake of sodium is higher than the excretion, it will break the metabolic balance in the body, hinder the absorption of other nutrients, cause systemic edema, lead to hypertension, induce cardiovascular and cerebrovascular diseases, and seriously endanger people's lives. When the intake of sodium is less than the excretion, it will not meet the needs of the human body for sodium, and it will suffer from "sodium deficiency". Its symptoms are: physical fatigue, apathy, nausea, blurred vision, increased heart rate, low blood pressure, weak pulse, muscle spasm, unstable standing and fainting, and even severe kidney and heart failure, which will also endanger people's lives. At present, "lightness" is popular, but lightness should have a "degree". Now some people regard "no dizziness and no salt" as the way to live longer, which is not so scientific. The International Health Organization recommends that adults need about 6 grams of salt every day, which is the necessary amount for the human body every day. But according to the taste of China people, the daily salt intake of adults is 2-3 times that of 6 grams. As we all know, manual workers sweat more, so the amount of sodium excreted through sweat glands is more. People have made a lot of efforts, so it is reasonable to eat more salt. In summer, people in love sweat, and if they don't get timely sodium supplementation, people will be at home. Because of the strong sunshine in the west of China, people there especially like to eat salty food, which is determined by climatic factors. Judging from people's daily habits, eating spicy food is related to weight and lightness. Spicy food can stimulate sweat gland secretion and promote sodium metabolism. As we all know, Sichuanese love to eat hot pot, which is too salty, but too spicy, which is probably the reason.

Salt also plays a very important role in the human body, that is, as a carrier of iodine supplementation, "iodized salt" is enforced nationwide by the state. Iodine is an essential trace element for human body. The international health organization recommends that the daily intake of adults is 150-300 micrograms. We should not underestimate it. Once the human body is short of iodine, it will do great harm to human health. It can induce hyperthyroidism and cretinism. Symptoms of hyperthyroidism: thick neck, prominent eyes, fear of heat, sweating, diarrhea, easy hunger, palpitation, emaciation, muscle weakness, hand tremor, irregular menstruation of women, irritability, which often leads to disharmony in family, neighborhood and society. Seriously, it will also lead to many diseases such as mental, cardiovascular, musculoskeletal and reproductive systems, thus endangering human health and life.

Historically, before iodized salt appeared, "hyperthyroidism" patients were everywhere, and idiots and semi-idiots appeared in the crowd because of cretinism. Almost every village, big or small, exists to varying degrees. There are more deaf-mute people, semi-deaf people and people with low IQ, and "idiot families" are also common, especially in mountainous areas. This cannot be said to have nothing to do with iodine deficiency in some parts of China.

Once again, I appeal to people who have the habit of not eating and not eating high-iodine seafood. To buy salt, you need to choose iodized salt.