The human body is composed of chemical elements, and there are more than 60 kinds of elements that make up the human body. Among them, calcium, sodium, potassium, magnesium, carbon, hydrogen, oxygen, sulfur, nitrogen, phosphorus, chlorine and other essential quantitative elements 1 1 are concentrated in the first 20 elements of the periodic table, as well as iron, copper, zinc, manganese, cobalt, vanadium, chromium, molybdenum, selenium and iodine. Among them, calcium, sodium, potassium and magnesium account for more than 99% of the total metal ions in human body. Most of them exist in human body in the form of compounds, which transmit various substances necessary for life and play a role in regulating human metabolism. When a certain element in the diet is lacking or insufficient, it will affect human health. The following are the functions of several elements in the human body:
Nitrogen is an important element in protein, accounting for 16% ~ 18% of the molecular weight of protein. Protein is the main component of cell membrane, nucleus and various organelles. Enzymes in animals and plants are also composed of protein. In addition, nitrogen is an important component of nucleic acid, cephalin, lecithin, chlorophyll, plant hormones and vitamins. Because nitrogen plays an extremely important role in plant life activities, people call nitrogen a life element. When plants lack nitrogen, the old organs suffer first, and then the growth of the whole plant is seriously hindered. Plants are short and thin, with few branches, yellowish leaves, few seeds and low yield. Protein is the main component of organisms, and many kinds of protein can make organisms exist and continue. For example, there is hemoglobin; There is an indispensable catalyst for chemical changes in organisms-enzyme (a large class of complex protein); There are muscle proteins that undertake sports functions; There are also immune antibody proteins and so on. All kinds of protein are composed of various amino acids. Nitrogen is the main component of various amino acids.
Sodium and chlorine appear in the form of sodium chloride in human body, which plays a role in regulating osmotic pressure inside and outside cells and maintaining body fluid balance. The human body must supplement 4 ~ 10g of salt every day.
Calcium is an essential element for life and the most abundant metal element in human body, second only to C, H, O and N. The calcium content of normal people is about 1 ~ 1.25 kg. The average fat-free tissue content per kilogram is 20 ~ 25g. Calcium is an important component of human bones and teeth. Participate in various enzyme reactions and blood coagulation, maintain the normal contraction of myocardium, inhibit the excitement of neuromuscular, and consolidate and maintain the integrity of cell membrane. Calcium deficiency can cause rickets, nervous relaxation, convulsions, osteoporosis, poor coagulation mechanism and soreness of waist and legs. The human body should supplement 0.6 ~ 1.0g of calcium every day.
Iron is the main component of hemoglobin, and insufficient iron intake will cause iron deficiency anemia.
Phosphorus is the main element of human body, accounting for about 1% of body weight, and is the constituent element of ATP, DNA and other important compounds in the body. The human body needs to supplement about 0.7g of phosphorus every day.
Iodine is the raw material for synthesizing thyroid hormone. Iodine deficiency will affect children's growth and intellectual development, leading to dementia; Can cause goiter in adults.
For the sake of human health, we should pay attention to the balance of diet in our daily life, especially the supplement of the above elements and other trace elements (such as copper, potassium, magnesium, fluorine, selenium, zinc, etc.). ) to ensure normal physiological function.
The following is a comparison table of various elements with their physiological functions and daily sources:
element
physiological function
source
natrium
Maintain the acid-base balance of plasma
Salt.
potassium
Activator of enzyme
Vegetables (plants need potassium for growth, and plants contain more potassium).
calcium (Ca)
The indispensable elements of hard tissues such as bones are also closely related to the contraction of muscles. They participate in many enzyme reactions and blood coagulation, maintain the normal contraction of myocardium, inhibit the excitement of neuromuscular, and consolidate and maintain the integrity of cell membrane.
Food is rich in calcium (but be careful not to eat it with water-insoluble substances generated by calcium): animal bones, eggs, fish, shrimp and beans are rich in calcium.
magnesium
Activator of enzyme
Green vegetables (chlorophyll is rich in magnesium), beans, shrimps and crabs
zinc (Zn)
Zinc deficiency will lead to malnutrition, imbalance of reproductive system, certain activity to enzymes and certain stability to protein.
Beans, lean meat, rice and noodles
copper
Copper is an active element of many enzymes, which can promote cell maturation, catalyze redox reaction in vivo, promote iron absorption and utilization, and cooperate with hematopoiesis. Lack of copper can cause anemia and dysplasia. Another more important function of copper is to assist DNA replication.
Animal liver, green leafy vegetables, mollusks, etc. Are rich in copper.
iron
Iron is the main component of heme, and its main function is to transport oxygen to all cells in the body and expel CO2. Iron deficiency can cause anemia.
Animal liver, egg yolk, kelp, seaweed, spinach (avoid drinking tea when eating iron-rich substances).
phosphorus (P)
Phosphorus is mainly distributed in bones, teeth, blood, brain and adenosine triphosphate, among which adenosine triphosphate is the energy warehouse of human body.
Meat, shrimp, fish, milk, beans and so on.
iodine
A component of thyroxine, iodine deficiency can lead to pachycephaly.
Kelp, seaweed, sea cucumber.
fluorine
It exists in bones and teeth. Lack of fluoride can cause dental caries, but excessive fluoride can cause "skeletal fluorosis" and "mottled glaze".
Fluorine toothpaste
selenium
It is a component of some enzymes and has certain anticancer effect. Selenium deficiency can lead to cardiovascular diseases, hemolytic anemia and Keshan disease.
Dried rice, meat, animal liver, rice, garlic, mustard, etc.