Recommended intake: The Nutrition Society of China suggests that adult men need about 350 mg of magnesium every day, adult women need about 300 mg, and pregnant women and lactating women need about 450 mg (peanuts can be eaten 2-3 times a week, and 5-8 capsules each time can meet the demand for magnesium).
Magnesium is an essential trace element for mammals and humans. It is an important cation in cells and participates in the synthesis of protein and muscle contraction.
Magnesium deficiency is mainly manifested as emotional anxiety, excitability, hand and foot convulsions, hyperreflexia and so on. Under normal circumstances, due to the regulatory effect of the kidney, magnesium poisoning generally does not occur when excessive magnesium is taken orally. When renal insufficiency occurs, a large amount of oral magnesium can cause magnesium poisoning, which is manifested as abdominal pain, diarrhea, vomiting, polydipsia, fatigue and weakness, and in severe cases, dyspnea, cyanosis and dilated pupils.
Magnesium is widely distributed in plants, more in muscles and organs and less in dairy products. The utilization rate of magnesium in animal food is high, reaching 30% ~ 40%, while the utilization rate of magnesium in plant food is low. The requirement of magnesium is 150mg for 2-3 years old and 200mg for 3-6 years old.
Cramp "eat more foods containing magnesium."
Many people are prone to "cramps" in their legs when they sleep at night, which is called "convulsions" in medicine, especially when they catch a cold at night. Many people blame it on calcium deficiency, but judging from the human body's demand for minerals and trace elements, this symptom can also occur when magnesium is deficient.
Magnesium plays a very important role in human motor function activities. People live by a series of complex biochemical reactions in the human body, and thousands of enzymes (biocatalysts) are needed to catalyze these biochemical reactions. Foreign scientists have found that magnesium can activate 325 kinds of enzyme systems, and it is well-deserved to call magnesium an activator of life activities. In recent years, foreign scientists pointed out that people should eat magnesium after middle age. That is, eat more foods rich in magnesium. Cardiovascular diseases, such as coronary heart disease, hypertension, hyperlipidemia, myocardial infarction, diabetes, etc., mostly occur after middle age and are related to the decrease of magnesium content in the body.
Magnesium is the intracellular positive ion second only to potassium in human body. It participates in a series of metabolic processes in the body, including the formation of bones and cells, and is closely related to neuromuscular and cardiac functions. The daily demand of magnesium for ordinary adults is 350 mg for men and 300 mg for women. If magnesium is lacking, muscle weakness and endurance will be reduced. Because exercise, especially long-term high-intensity exercise, will consume a lot of magnesium in the body, reduce muscle activity, and even cause convulsions and spasms.
Experts believe that under normal food intake, there is generally no problem of magnesium deficiency and magnesium supplement. If magnesium deficiency symptoms occur, you should choose foods rich in magnesium: cereals, beans, green vegetables, egg yolks, beef, pork, seafood products, peanuts, sesame seeds, bananas and so on. Tofu also contains high magnesium content. Eating some brine tofu often can solve the "convulsion" caused by magnesium deficiency. [Edit this paragraph] Related information Magnesium is one of the ten most widely distributed elements in nature, but it has not been discovered for a long time because it is not easy to be reduced to a simple state from compounds.
For a long time, chemists have regarded magnesia bitter soil obtained by roasting magnesite containing magnesium carbonate as an inseparable substance. It was included in the list of elements published by lavoisier in 1789. 1808, after David successfully prepared calcium, he successfully prepared magnesium by the same method. Since then, magnesium has been identified as an element, named magnesium, and the symbol of the element is Mg. Magnesium comes from the city of magnesium oxide in Greece, because magnesium oxide is produced near this city and is called magnesium oxide alba, that is, white magnesium oxide. But the name magnesium is easily confused with the name manganese. Although some people have proposed to change it, they have been using it.
Magnesium is an essential element to participate in the normal life activities and metabolic processes of organisms. Magnesium affects many biological functions of cells: it affects the transport of potassium ions and calcium ions, regulates signal transmission, and participates in energy metabolism, protein and nucleic acid synthesis; The structure and function of substances can be maintained by complexing negatively charged groups, especially phosphate groups in nucleotides; Activation and inhibition of catalytic enzymes and their regulation on cell cycle, cell proliferation and cell differentiation; Magnesium is also involved in maintaining the stability of genome, and is also related to oxidative stress and tumorigenesis.
Absorption and metabolism of magnesium: The total magnesium content in adults is about 25g, of which 60%~65% exists in bones and teeth, and 27% is distributed in soft tissues. Magnesium in food can be absorbed in the whole intestine, but mainly in the jejunum and ileum, and the absorption rate is generally around 30%. The main components that promote magnesium absorption in diet are amino acids, lactose and so on. The main components that inhibit magnesium absorption are excessive phosphorus, oxalic acid, phytic acid and dietary fiber. A large amount of magnesium ingested by adults is secreted into the intestine from bile, pancreatic juice and intestinal juice, of which 60%~70% is excreted with feces, and some is lost from sweat and exfoliated skin cells.
Magnesium ion is a kind of positive ion with more content in organisms, and its quantity is second only to calcium, sodium and potassium, ranking fourth; The content of magnesium ion in cells is second only to that of potassium ion. Whole seeds, unbroken grains, green leafy vegetables, beans and nuts are the richest sources of dietary magnesium. The content of magnesium in fish, meat, milk and fruit is low; Almost all magnesium in processed food is lost during processing. Creatine hexaphosphate, crude fiber, ethanol, excessive phosphate and calcium ions weakened the absorption of magnesium, which may be due to the decrease of magnesium concentration in the lumen.
Magnesium can effectively promote the absorption of calcium. There is a special calcium channel in the cell, and its main element is magnesium. Therefore, magnesium deficiency in human body will affect calcium metabolism. [Edit this paragraph] Introduction to magnesium deficiency.
Magnesium is the main cation in human cells, which is concentrated in gland particles, second only to potassium and phosphorus, and second only to sodium and calcium in extracellular fluid. It is an essential substance for basic biochemical reactions of many cells in the body. The atomic order of magnesium is 12 and the atomic weight is 24.3. It is a typical bivalent metal with the common characteristics of metals. Because the oxide properties of magnesium are between "alkaline" and "soil" like calcium, it is called alkali metal element. The total content of magnesium in normal adults is about 25g, of which 60%-65% exists in bones and teeth, and 27% is distributed in soft tissues. Magnesium is mainly distributed in cells, and the magnesium in extracellular fluid does not exceed 65438 0%. Magnesium is an essential substance for the metabolism of calcium, vitamin C, phosphorus, sodium and potassium, and plays an important role in the normal operation of neuromuscular function and blood sugar conversion.
The discovery of magnesium
Many centuries ago, the ancient Romans believed that "magnesium oxide" (a white magnesium salt produced in Greece, hence the name magnesium) could treat many diseases. Until 1808, the British chemist David separated the element magnesium by electrolysis of bitter soil (containing magnesium). MoCollum, E.V. and their colleagues used rats and dogs as experimental animals for the first time in the early 1930s, and systematically observed the reaction of magnesium deficiency. 1934 published the first clinical report of magnesium deficiency in minority people based on different diseases. It has been proved that magnesium is an essential element for human body. Flink and his colleagues reported cases of magnesium deficiency due to alcoholism and magnesium-free intravenous infusion in the early 1950s. Magnesium deficiency generally does not occur in healthy people, but it has been found that more and more clinical diseases are related to magnesium deficiency.