Take the test
Do you have problems with vitamin K?
This important vitamin needed for proper blood clotting, bone metabolism and connective tissue, normal operation liver. Take the test and find out if everything is ok with this vitamin?
On-line consultations of doctors
Antivitamins
We all know what vitamins are and how important they are for our health. But it turns out that there are also antivitamins. Antivitamins are chemical compounds, which are similar in structure to vitamins, but have opposite properties.
Antivitamins were accidentally discovered back in the 70s of the last century. Then, working on the synthesis folic acid(vitamin B9), scientists unexpectedly received folic acid with exactly the opposite properties. It turned out that the analog completely lost vitamin value, but at the same time it has an important property - it inhibits the development of cells, especially cancer cells. This newly synthesized compound was subsequently used in medicine for the treatment of certain types of neoplasms.
According to the mode of action, antivitamins can be divided into two groups. The first group includes substances that enter into direct interaction with the vitamin, as a result of which the latter loses its biological activity. The essence of their antivitamin action is that in one way or another they destroy the vitamin molecule or bind it in such a way that it loses the properties that give it biological activity. For example, one of the proteins found in eggs, avidin, binds to biotin (vitamin H) and forms a compound (avidin-biotin complex), in which biotin is inactive, insoluble in water, not absorbed from the intestine and cannot be used by the body as a coenzyme. As a result, vitamin H deficiency develops. Therefore, avidin is an anti-vitamin H.
As another example of antivitamins of the first group, one can cite the enzyme ascorb oxidase, under the action of which ascorbic acid is oxidized. Other enzymes that destroy vitamins are also known: thiaminase - destroys thiamine (vitamin B1), lipoxidase - destroys provitamin A, and others.
The second group of antivitamins are structural analogues vitamins, in which one or another functionally important group replaced by another, which deprives the molecule of its vitamin activity. This - special case typical antimetabolites. Antimetabolites are substances related to chemical structure to metabolites, that is, compounds that play important role in metabolism. A classic example of such antivitamins (antimetabolites) is sulfanilamide (an antimicrobial agent).
Antivitamins play a positive and negative role in our lives.
Negative Role:
- Neutralize the action of vitamins, block their absorption.
positive role:
- Antivitamins perform a kind regulatory function in the vitamin balance of the body, protect the latter from harmful effects excess intake from food or excessive biosynthesis of the corresponding vitamins. These "limiters" are probably especially important in relation to those vitamins to which the body is especially sensitive to excess.
- The study of antivitamins opens up remarkable prospects in the field of creating new medicines.
Many drugs are antimetabolites, inhibitors (retarders, suppressors) of enzymatic processes. On this principle of blocking the active centers of enzymes pathogenic microorganisms based therapeutic effect antibiotics. Some chemotherapy drugs have a curative effect on certain types malignant tumors because they inhibit the enzymes responsible for the excess biosynthesis of nucleic acids and proteins in these diseases. And a prominent place among such medicines is occupied by antivitamins.
The following are some examples of antivitamins or vitamin antagonists.
Vitamin A antagonists
Blood-thinning drugs and other drugs, including aspirin, phenobarbital, dicoumarol, destroy vitamin A in the body.
Vitamin K antagonists
Vitamin K deficiency is highly unlikely because this vitamin is found in a wide variety of commonly eaten foods. herbal products and synthesized by bacteria in the intestinal tract. but antibiotic therapy(taking any antibiotics, such as penicillin, streptomycin, tetracycline, chloromycin, teramycin, etc.) inhibits the growth of bacteria, including the synthesis of vitamin K.
It is unlikely that today there is a person who does not know about myocardial infarction or thrombosis of cerebral vessels. At the heart of these menacing phenomena is often increased clotting blood. If for any reason heart vessel becomes impassable for blood, the section of the heart muscle supplied by this vessel ceases to receive the substances it needs and necrotizes (dies off). Similarly, the nutrition of one or another part of the brain is disturbed when the vessel that supplies it with blood is obstructed. One of common causes such obstruction blood vessels is the blockage of their lumen by a clot of clotted blood - a thrombus. Such a thrombus can form not only from the blood that has clotted in the vessel itself that is clogged by it - it sometimes forms in some other place in the vascular system. At healthy person intravascular formation of blood clots that can block their lumen does not occur, but it can occur if there is a violation normal state the walls of blood vessels, in particular, with atherosclerosis or increased blood clotting. Exclusively effective tool prevention of thrombosis with increased blood clotting and treatment of thrombosis dicoumarin- Vitamin K antagonist. Since the chemical structure of discoumarin is similar to the chemical structure of vitamin K, they act as anticoagulants, preventing the synthesis of prothrombin and other natural factors blood clotting.
Vitamin C antagonists
It is well known that cigarette smokers have lower levels of vitamin C than non-smokers. A Canadian physician, Dr. WJ McCormick (1), tested the blood levels of vitamin C in nearly 6,000 smokers. All were below normal readings. Similar results have been found in other studies. Friedrich Klenner, MD, has been quoting for years that one cigarette can deplete as much as thirty-five milligrams of vitamin C from the body. (Calcium and phosphorus, both minerals, are also depleted by cigarettes.) Because vitamin C reacts with any foreign substance in the blood, all drugs and contaminants can be considered vitamin C antagonists. Some of the better known vitamin C antagonists include ammonium chloride, thiuracil, atropine, barbiturates, and antihistamines. Alcoholic drinks are also vitamin C antagonists, as are all stresses (emotional outbursts and frustrations, extreme temperatures, drugs).
Vitamin antagonists of B vitamins
Antifolates are folic acid antagonists. As mentioned above, it was found that some antifolates inhibit cell division, which made it possible to use them for the treatment of certain types of tumors. Antifolates have attracted attention for yet another reason. Folic acids are essential factors for the growth and reproduction of all microorganisms. Therefore, one could count on the fact that antifolates - structural analogues of folic acids - would be valuable means of combating pathogenic microorganisms. These hopes were justified. Among the many synthesized analogs of folic acids, inhibitors of bacterial growth have been found. Today, on the basis of antifolates, effective drugs for the treatment of human and animal diseases caused by protozoa and bacteria. Antifolates have been synthesized that are no worse than quinine in suppressing the growth of the causative agent of malaria, and one of them, pyrimethamine, is used as an antimalarial drug. The same antifolate is used to treat toxoplasmosis, a disease caused by Toxoplasma gondii. Synthesized antifolate, which has found application as a treatment for cholera.
Antivitamin riboflavin (vitamin B2) - quinacrine. It is used to treat malaria, helminthiasis.
Natural antivitamins that enter the human body with food can cause disease. Back in 1936, a disease was described that was observed among foxes kept on a farm when they were given raw fish - carps with food. It turned out that it was vitamin B1. It turned out that carp entrails are rich in thiamipase, an enzyme that destroys thiamine (vitamin B1). In subsequent studies, this enzyme was found in the bodies of others. freshwater fish, molluscs, some plants, microorganisms. This is one of many reasons not to eat Japanese food, sashimi (raw fish), or any other raw seafood.
In the food products used by the population of Indonesia, an antimetabolite of vitamin B2, the so-called toxoflavin, was found, which turned out to be the cause of poisoning of people. Essence toxic action This antimetabolite is as follows: it turns off the action of respiratory enzymes containing vitamin B2 in its composition.
Birth control pills - antivitamins riboflavin, vitamin B6, vitamin B12 and folic acid. It has been found that women taking oral contraceptives have much more low levels riboflavin than the control group who did not use oral contraceptives. These contraceptives are especially harmful to vitamin B12 and folic acid. estrogen in oral contraceptives It is also a vitamin E antagonist.
Vitamin antagonists of vitamin PP
Some cereals contain an analogue of vitamin PP - the so-called acetyl-3-pyridine, which causes vitamin deficiency PP (pellagra) in humans.
The practical significance of antivitamins is not limited to their increasing use in the treatment of human and animal diseases. Their ability to block vital metabolic links in Lately began to be used to combat pests of agricultural crops and carriers of infections. So, one of the antivitamins B6, known under the name "Castrix", is widely used as a powerful poison to control rodents.
Literature
1. Antivitamins for Medicinal Applications Chembiochem. 2015 Jun 15;16(9):1264-78. doi: 10.1002/cbic.201500072. Epub 2015 May 25.
2. I.I. Matutsis. Vitamins and antivitamins M., "Sov.Russia", 1975, 240 s
The site administration site does not evaluate recommendations and reviews about treatment, drugs and specialists. Remember that the discussion is not only conducted by doctors, but also by ordinary readers, so some advice may be dangerous to your health. Before any treatment or taking medications, we recommend that you consult a specialist!
AntivitaminsSince childhood, we know that our body needs vitamins. However, there are substances that suppress their action.
Such substances are called - "antivitamins", they were discovered more than 40 years ago. During the experiment on the synthesis of vitamin B9 (folic acid), it was noticed that the synthesized acid lost its vitamin activity and acquired the opposite properties.
Further studies showed that there really are substances that, when they enter the body, enter into metabolic reactions instead of vitamins and change the course of these reactions. As a result, no matter how many vitamins a person takes, there will be no effect, it will be nullified by those very antivitamins.
deceptive maneuver
Vitamins and antivitamins have similar chemical structures. In the body, vitamins are converted into coenzymes and interact with specific proteins, thus regulating various biochemical processes.
Antivitamins also turn into coenzymes, only false ones. They replace the true coenzymes of vitamins, but cannot play their role. Specific proteins do not notice the substitution and try to perform their usual functions. But this is no longer possible, metabolic processes are disturbed, because they cannot occur without their catalyst - vitamins. Moreover, the false coenzyme begins to participate in the processes itself, playing its own biochemical role.
Thus, the action of vitamins can be completely or partially blocked, their biological activity is reduced or completely reduced to nothing.
"Sweet Couples"
Most a prime example a similar "vitamin conflict" is vitamin C (ascorbic acid) and its antagonists ascorbate oxidase and chlorophyll. Both of these substances contribute to the oxidation of vitamin C. How does this manifest itself in everyday life? If you cut apples into slices, then after a while it will darken - that is, it will oxidize. And at the same time lose up to 50% ascorbic acid. The same goes for the salad. fresh vegetables, and with freshly squeezed juices - all this is more useful to eat immediately after cooking.
Vitamin B1 (thiamine) is responsible for the normal course of growth and development and helps maintain proper heart function,
nervous and digestive systems. But all its positive properties are destroyed by thiaminase. This substance enters the body from raw foods: mainly fresh and sea fish, but small amounts of thiaminase are also found in rice, spinach, potatoes, cherries, and tea leaves. So the fans Japanese cuisine there is a risk of earning a vitamin B deficiency.
Incidentally, it is in raw foods especially many antivitamins are found. So, for example, raw beans neutralize the effect of vitamin E. And soybeans contain a protein compound that completely destroys vitamins D, calcium and phosphorus, provoking the development of rickets.
Another very popular antivitamin that many people don't even know about is caffeine, found in tea and coffee. Caffeine interferes with the absorption of vitamins B and C in the body. To resolve this conflict, it is better to drink tea or coffee an hour and a half after eating.
Related chemical structures are biotin and avidin. But if biotin is responsible for healthy intestinal microflora and stabilizes blood sugar levels, then avidin prevents its absorption. Both substances are found in egg yolk, but avidin is only in a raw egg,
and it breaks down when heated.
If your diet is dominated by foods such as brown rice, beans and soybeans, mushrooms and oyster mushrooms, cow's milk and beef, walnuts, then there is a risk of hypovitaminosis PP (niacin). Since these products are rich in its antipode - the amino acid leucine.
Vitamin A (retinol), although it belongs to fat-soluble vitamins, is poorly absorbed with an excess of margarine and cooking fats. Therefore, when cooking liver, fish, eggs rich in retinol, the minimum amount of fat should be used.
And the main enemy of vitamins is, of course, alcohol and tobacco (including second hand smoke). Alcohol is especially responsible for the destruction of vitamins B, C and K. One cigarette removes from the body daily allowance vitamin C.
And they heal and cripple ...
Medications are also a kind of antivitamins. Many modern medications destroy vitamins or interfere with their absorption. For example, the well-known aspirin washes out potassium, calcium, vitamins C and B from the body.
B vitamins are also destroyed when taking antibiotics,
that destroy beneficial microflora intestines and this causes fungal diseases, for example, thrush. But all the B vitamins are partially formed precisely by intestinal bacteria, sometimes it is enough to eat more yogurt, acidophilus, so that the intestinal microflora returns to normal.But the properties of antivitamins are used for good. For example, vitamin K contributes to increased blood clotting, and its antipode dicoumarin, on the contrary, reduces it, which is necessary for certain diseases.
Acrikhin and quinine are antagonists of riboflavin (vitamin B) and are excellent treatment for malaria.
Eliminate competition
Thus, in any food product there are both vitamins and their antagonists. There are usually more of the first than of the second, and this ratio is optimal; you should not change it yourself in one direction or another.
Do you eat right and balanced, eat vegetables, fruits and cereals rich in fiber, macro- and microelements and vitamins? But these substances in our products can negate the effect of vitamins and provoke beriberi. Or, on the contrary, they will become a means of treating many diseases. Meet Antivitamins.
Antivitamins are compounds that are similar in chemical structure to vitamins, but have a completely opposite effect on humans. Once in the body, antivitamins are included instead of vitamins in metabolic reactions and inhibit or disrupt their normal course. This leads to vitamin deficiency even when certain vitamin naturally supplied with food in sufficient quantities.
A classic example: you cut open an apple and left one half for later, which begins to darken over time. Yes, we all remember about the effects of oxygen and oxidation, but there is practically no vitamin C left in this darkened half. Under the influence of light in an apple, ascorbinase is produced - a substance similar in chemical structure to vitamin C, but with the opposite effect. It causes the oxidation of vitamin C and its destruction. There is a lot of it in fresh fruits and vegetables, especially in apples, cucumbers, herbs and zucchini. Therefore, eat them immediately fresh or process them thermally.
Antivitamins are known for almost all vitamins.
Thiaminase
Vitamin B1 (thiamine) antivitamin. This enzyme destroys its useful rival. An excess amount of thiaminase in the body can cause hypovitaminosis B1. This harmful enzyme is found in the tissues of some types of raw (salted and dried) freshwater and sea fish. Avoiding trouble is very simple: the enzyme, like any other protein, folds and loses activity when heated. Therefore, the fish should simply be boiled, baked or fried. And do not turn popular sushi into a daily dish.
Thiaminase 2
The vegetable form of the enzyme is found, for example, in Brussels sprouts, Savoy sprouts, rice, spinach, and raw potatoes. Thiaminase 2 easily disappears when heated, so only fanatical raw foodists need to be careful.
Avidin
Antivitamin of vitamin H, biotin, vitamin B7 and coenzyme R. Avidin binds vitamin H and removes it in transit from the body. It is found in raw egg white. Of course, because of the fear of salmonellosis, few people now consume raw chicken eggs, but many housewives continue to do protein creams. It's best to skip this sugary addition, as even in a washed egg, salmonella can survive. Moreover, in fried and boiled eggs essential vitamin H remains, and avidin disappears.
Caffeine
Surprised? Something without which many of us cannot cheer up is a very popular antivitamin. It interferes with the absorption of vitamins C and group B. To resolve this conflict, it is better not to drink tea or coffee in the morning on an empty stomach, and even more so to replace whole foods with them. It is better to consume these drinks during meals or an hour and a half after meals.
Amino acid leucine
The antipode of vitamin PP (niacin). If your diet is rich in brown rice, beans, soybeans, walnuts, champignons and oyster mushrooms, cow's milk and beef, then there is a risk of vitamin PP deficiency. Also do not forget about heat treatment. In addition to leucine, vitamin PP has 2 more antivitamins: indoleacetic acid and acetyl pyridine. These substances are abundant in corn.
hydrogenated fats
They are very harmful to retinol - vitamin A. Although retinol is fat-soluble, it is poorly absorbed with an excess of margarine and special cooking fats. When cooking liver, fish, eggs, carrots, and other retinol-rich foods, use as little fat as possible. If you fry these products, it is better in classic sunflower, olive or butter. We also advise you not to add margarine when baking. Of course, this cooking oil is much cheaper, but it is also much more harmful.
Polyunsaturated fatty acid
Useful, in general, compounds with their overabundance turn into poison. Polyunsaturated fatty acids, which are part of vegetable and soybean oils, as well as legumes, are an antagonist of vitamin E. Therefore, even with healthy fats need to be vigilant. By the way, soya beans If consumed in excess, they can also kill vitamin D.
Dicoumarin
Competitor of vitamin K. Antivitamin reduces the effect of phylloquinone (vitamin K) and is found in figs, parsnips and in a plant such as sweet clover.
Benefits and Benefits of Antivitamins
Antivitamins were discovered by accident when scientists tried to enhance the properties of vitamin B9 (folic acid), which activates the processes of hematopoiesis. But as a result of various chemical processes vitamin B9 was transformed, lost its usual properties, but acquired new ones - it began to slow down growth cancer cells.
Render positive influence maybe dicoumarin is an antagonist of vitamin K. Both of these substances are involved in the processes of hematopoiesis. That's just vitamin K contributes to blood clotting, and dicoumarin disrupts it. Now the property of this antivitamin is used to treat related diseases.
Therefore, our main advice is to observe the measure. Eat most foods immediately and do not store or heat them for a long time. Heat treatment is also not always harmful. Especially the brew. Also, serious enemies of vitamins were and remain alcohol and smoking - another reason to get rid of bad habits.
Prepared using materials: zdr.ru, zdorovja.com.ua, polonsil.ru, fizrazvitie.ru
The history of the discovery of vitamins
By the second half of the 19th century it was clear that the nutritional value food is determined by the content in them, mainly of the following substances: proteins, fats, carbohydrates, mineral salts and water.
It was generally accepted that if human food includes in certain quantities all these nutrients, then it fully meets the biological needs of the body. This opinion was firmly rooted in science and was supported by such authoritative physiologists of the time as Pettenkofer, Voit and Rubner.
However, practice has not always confirmed the correctness of the ingrained ideas about the biological usefulness of food.
The practical experience of doctors and clinical observations have long undeniably indicated the existence of a number of specific diseases directly related to malnutrition, although the latter fully met the above requirements. This was also evidenced by the centuries-old practical experience of participants in long journeys. A real scourge for sailors long time had scurvy; more sailors died from it than, for example, in battles or from shipwrecks. So, out of 160 members of the famous expedition of Vasco de Gama, who laid sea route in India, 100 people died from scurvy.
The history of sea and land travel also gave a number of instructive examples, indicating that the occurrence of scurvy can be prevented, and scurvy patients can be cured, if a certain amount is introduced into their food. lemon juice or decoction.
Thus, practical experience clearly showed that scurvy and some other diseases are associated with malnutrition, that even the most abundant food by itself does not always guarantee the absence of such diseases, and that in order to prevent and treat such diseases, it is necessary to introduce into the body what - some additional substances that are not found in any food.
Experimental substantiation and scientific and theoretical generalization of this centuries-old practical experience first became possible thanks to the study of the Russian scientist Nikolai Ivanovich Lunin, who opened a new chapter in science, who studied in the laboratory of G.A. Bunge role minerals in nutrition.
N.I. Lunin conducted his experiments on mice kept on artificially prepared food. This food consisted of a mixture of purified casein (milk protein), milk fat, milk sugar, milk salts, and water. It seemed that all the necessary components of milk were present; meanwhile, mice that were on such a diet did not grow, lost weight, stopped eating the food given to them, and finally died. At the same time, a control batch of mice treated with natural milk developed quite normally. Based on these works, N.I. Lunin in 1880 came to the following conclusion: "... if, as the above experiments teach, it is impossible to provide life with proteins, fats, sugar, salts and water, then it follows that in milk, in addition to casein, fat, milk sugar and salts, there are still other substances indispensable for nutrition. It is of great interest to investigate these substances and study their importance for nutrition. "
It was important scientific discovery, refuted the established position in the science of nutrition. The results of the work of N. I. Lunin began to be disputed; they were tried to be explained, for example, by the fact that the artificially prepared food with which he fed the animals in his experiments was supposedly tasteless.
In 1890 K.A. Sosin repeated the experiments of N.I. Lunin with a different version of the artificial diet and fully confirmed the conclusions of N.I. Lunin. Yet even after that, the impeccable conclusion did not immediately receive universal recognition.
A brilliant confirmation of the correctness of N.I. Lunin was the establishment of the cause of the beriberi disease, which was especially widespread in Japan and Indonesia among the population, which ate mainly polished rice.
Doctor Aikman, who worked in a prison hospital on the island of Java, noticed in 1896 that chickens kept in the hospital yard and fed on ordinary polished rice suffered from a disease resembling beriberi. After switching the chickens to a diet of brown rice, the disease disappeared.
Aikman's observations, made on a large number of prisoners in Java prisons, also showed that among people who ate peeled rice, beriberi fell ill, on average, one person in 40, while only one person in 40 fell ill with beriberi in the group of people who ate brown rice. 10000.
Thus, it became clear that the shell of rice (rice bran) contains some unknown substance that protects against beriberi disease. In 1911, the Polish scientist Casimir Funk isolated this substance in crystalline form (which, as it turned out later, was a mixture of vitamins); it was quite resistant to acids and withstood, for example, boiling with a 20% sulfuric acid solution. IN alkaline solutions the active principle, on the contrary, was destroyed very quickly. By their own chemical properties this substance belonged to organic compounds and contained an amino group. Funk came to the conclusion that beriberi is only one of the diseases caused by the absence of certain specific substances in food.
Despite the fact that these special substances are present in food, as N.I. Lunin, in small quantities, they are vital. Since the first substance of this group of vital compounds contained an amino group and possessed some of the properties of amines, Funk (1912) proposed calling this entire class of substances vitamins (lat. vita - life, vitamin - amine of life). Subsequently, however, it turned out that many substances of this class do not contain an amino group. However, the term "vitamins" has become so firmly established in everyday life that it no longer made sense to change it.
After being separated from food products a substance that protects against beriberi disease, a number of other vitamins have been discovered. Great importance The work of Hopkins, Stepp, McCollum, Melenby, and many other scientists contributed to the development of the theory of vitamins.
About 20 are currently known. various vitamins. Their chemical structure has also been established; this made it possible to organize the industrial production of vitamins not only by processing the products in which they are contained in finished form, but also artificially, by means of their chemical synthesis.
General concept about avitaminosis; hypo- and hypervitaminosis
Diseases that occur due to the lack of certain vitamins in food are called beriberi. If the disease occurs due to the lack of several vitamins, it is called multivitaminosis. However, typical clinical picture avitaminosis is now quite rare. More often you have to deal with the relative lack of any vitamin; this disease is called hypovitaminosis. If the diagnosis is made correctly and in a timely manner, then beriberi and especially hypovitaminosis can be easily cured by introducing the appropriate vitamins into the body.
Excessive introduction of certain vitamins into the body can cause a disease called hypervitaminosis.
Currently, many changes in metabolism in vitamin deficiency are considered as a consequence of a violation enzyme systems. It is known that many vitamins are part of enzymes as components of their prosthetic or coenzyme groups.
Many avitaminosis can be considered as pathological conditions arising on the basis of the loss of the functions of certain coenzymes. However, at present, the mechanism of the occurrence of many avitaminosis is still unclear, therefore, it is not yet possible to interpret all avitaminosis as conditions that arise on the basis of a violation of the functions of certain coenzyme systems.
With the discovery of vitamins and the elucidation of their nature, new prospects have opened up not only in the prevention and treatment of beriberi, but also in the field of treatment. infectious diseases. It turned out that some pharmaceuticals(for example, from the group of sulfanilamide) partially resemble in their structure and in some chemical features vitamins necessary for bacteria, but at the same time do not have the properties of these vitamins. Such "disguised as vitamins" substances are captured by bacteria, while active centers are blocked. bacterial cell, its metabolism is disturbed, and the death of bacteria occurs.
April 18th, 2018
Everyone knows what vitamins are, what are the benefits of them and where they are found in large quantities. Many books, articles and medical monographs have been written about them. But few people know that in nature there are substances that are very similar to them, but have absolutely opposite properties.
They were given the name - antivitamins.
Decades ago, chemists tried to synthesize and amplify biological properties vitamin B9 (folic acid), which activates the processes of hematopoiesis and is involved in protein biosynthesis. But the artificial vitamin B9 completely lost its activity and acquired other properties - the resulting compound inhibited the development of cancer cells, and soon it began to be used as an effective antitumor agent.
Antivitamins are chemical compounds that are similar in structure to vitamins, but are their absolute antipodes. Their structure is so similar to the structure of vitamins that they can completely take place in the structure of vitamin coenzymes. But with all this, they cannot perform the function of the latter. As a result, there are interruptions in the course of biochemical processes in the human body. If enough is accumulated a large number of antivitamins, maybe complete violation metabolism.
Antivitamins, occupying the niche of vitamins in the human body, prevent them from performing their functions. But like any substance, antivitamins have their negative and positive sides.
Negative aspects of antivitamins:
- Forming stable bonds with vitamins or their receptors, they are completely excluded from metabolism.
- Block the absorption of vitamins coming from outside.
- Catalyze the process of removing vitamins from the body.
- They destroy bonds between molecules in the structure of vitamins, thereby inactivating them.
- Antivitamins act as regulators of the absorption of vitamins, since both of them can be found in the same product. Due to this, hypervitaminosis occurs very rarely.
- There are scientifically proven facts that antivitamins prevent some diseases. In the future, it is possible to synthesize specific drugs from them.
- Substances synthesized from antivitamins affect blood function and are used as anticoagulants.
- One of the most positive effects of antivitamins is the inhibition of the growth of cancer cells. This substance was synthesized from vitamin B9 (folic acid), in an attempt to change its structure.
Vitamin C has an anti-vitamin called ascorbate oxidase. This enzyme is present in many fruits and vegetables. It should also be noted that it has another antipode - chlorophyll, which is a substance that gives vegetables and fruits a green color.
Ascorbate oxidase and chlorophyll accelerate the oxidation of vitamin C. As an example, the following can be presented: when cutting fresh fruit and vegetables is lost up to 50% useful substances for 15 minutes to 4-6 hours. So if you cut fruits and vegetables, then it is better to do it immediately before use, or it is better to eat them whole.
Vitamin B1 (thiamine) has its own antivitamin thiaminase, which blocks all beneficial features substances. Thiaminase is found in the meat of some fish, so you should not get involved in raw fish, for example, sushi. Since there is a risk of developing avitaminosis B1. This can be easily avoided by giving it heat treatment. Because when exposed to temperature, antivitamins are easily destroyed.
The next well-known representative of antivitamins is avidin. It is found in abundance in raw egg whites. Due to the use of avidin, the vital vitamin H (biotin), which is located in the yolk, will not be absorbed. In a healthy person, biotin is synthesized in the intestine, more precisely by its microflora. But with the slightest violation of bowel function, the level of biotin is greatly reduced. Therefore, it must be taken with food. Eggs should be eaten only after preliminary heat treatment.
Vitamin A (retinol) belongs to the fat-soluble vitamins, but despite this it is poorly absorbed when overuse cooking oils, butter and margarine. Therefore, when cooking big amount vitamin A, you need to use a small amount of fat.
Vitamin PP (niacin) also has its antipode. It is the amino acid leucine. If daily diet rich in soy, beans, brown rice, mushrooms, walnuts, beef and cow's milk, then the risk of developing niacin hypovitaminosis increases. In addition to leucine, vitamin PP has 2 more antivitamins: indoleacetic acid and acetyl pyridine. These substances are abundant in corn.
Antivitamin in relation to vitamin E are polyunsaturated fatty acids that are part of vegetable and soybean oils, legumes. Therefore, even with healthy fats, you need to be vigilant.
The most popular and most used antivitamin of ascorbic acid and B vitamins is caffeine. In order not to earn health problems and also consume your favorite drink containing caffeine, you need to consume it an hour before meals or an hour and a half after it.
Alcohol is an anti-vitamin for all vitamin groups, but it hits the B group, vitamins C and K more.
Tobacco and what is included in the composition modern cigarettes is also an anti-vitamin for all useful substances, but more for ascorbic acid. When smoking one cigarette, a person loses daily dose vitamin C (25-100 mg).
Modern drugs, and especially antibiotics, are the strongest antivitamins for group B, but they can also easily destroy the amount of vitamins in the body of any of their groups. As an example, acetylsalicylic acid(aspirin) accelerates the excretion of vitamin C from the body by 2-3 times.
In order to lead healthy lifestyle life, not only regular physical activity is necessary, but a rational and correct approach to nutrition. Especially in conditions big city where the lack of vitamins is especially acute. After all, without an adequate combination of nutrients and physical activity, you can soon earn a bunch of chronic diseases and injuries that will not make your life better.
Currently, antivitamins are usually divided into two groups: 1) antivitamins, which have a structure similar to the structure of a native vitamin and have an effect based on competitive relationships with it; 2) antivitamins that cause modification chemical structure vitamins or complicate their absorption, transport, which is accompanied by a decrease or loss of the biological effect of vitamins. Thus, the term "antivitamins" refers to any substance that causes, regardless of the mechanism of their action, a decrease or complete loss biological activity vitamins.
Structure-like antivitamins (some of which have already been mentioned earlier) are essentially antimetabolites and, when interacting with an apoenzyme, form an inactive enzyme complex, turning off the enzymatic reaction with all the ensuing consequences.
Antivitamin B12
In addition to structure-like analogues of vitamins, the introduction of which causes the development of true avitaminosis, there are antivitamins of biological origin, including enzymes and proteins that cause splitting or binding of vitamin molecules, depriving them of their physiological effect. These include, for example, thiaminases I and II, which cause the breakdown of vitamin B1 molecules, ascorbate oxidase, which catalyzes the destruction of vitamin C, and the protein avidin, which binds biotin into a biologically inactive complex. Most of these antivitamins are used as medicinal products with a strictly directed action on some biochemical and physiological processes.
In particular, from antivitamins fat soluble vitamins dicoumarol, warfarin and tromexane (vitamin K antagonists) are used as anticoagulants. Well-studied antivitamins of thiamine are oxythiamine, pyri- and neopyrithiamine, riboflavin - aterbine, acrichin, galactoflavin, isoriboflavin (they all compete with vitamin B2 in the biosynthesis of coenzymes FAD and FMN), pyridoxine - deoxypyridoxine, cycloserine, isonicotinoyl hydrazide (isoniazid), which has antibacterial action for Mycobacterium tuberculosis. Folic acid antivitamins are amino- and amethopterins, vitamin B12 - derivatives of 2-aminomethylpropanol-B12, nicotinic acid- isoniazid and 3-acetylpyridine, para-aminobenzoic acid - sulfanilamide preparations; they all found wide application as an anticancer or antibacterial agents, inhibiting the synthesis of protein and nucleic acids in cells.
Vitamins are catalysts for biochemical processes that, when ingested, turn into coenzymes, interact with specific proteins and speed up metabolism. Moreover, each enzyme and its corresponding vitamin are specific, i.e. vitamins can only be integrated into their corresponding protein (enzyme). And enzymes, in turn, can only perform a specific function and cannot replace each other.
Antivitamins have a similar structure to their corresponding vitamins. In the body, they turn into a false coenzyme and take the place of a real vitamin. Specific proteins do not notice the difference and try to perform their functions, but because of the antivitamin, nothing works. The biochemical process corresponding to the enzyme is stopped.
Specialists do not exclude that the resulting pseudoenzyme begins to play its no less important biochemical role. For example, similar changes in the structure are disrupted in Mycobacterium tuberculosis metabolic processes, as a result, delay the reproduction and growth of pathogens. Similar processes are observed in the action of antimalarial drugs. But not all antivitamins are used in medical practice. Chemists have already synthesized thousands of different vitamin derivatives, some of which have antivitamin properties, but most of them have weak pharmacobiological activity. Although it is quite possible that it is vitamin antagonists that will become the main means of combating diseases.
In food products, all substances, including vitamins and antivitamins, are in the optimal ratio - they complement each other. On the one hand, antivitamins are a natural regulator; competing with vitamins, they practically exclude hypervitaminosis, even if daily allowance vitamins will be greatly exceeded. On the other hand, antivitamins are involved in biochemical processes, ie. like vitamins, prevent some diseases. Therefore, if you start taking additional artificial vitamins, you can upset the balance. Vitamins, like other drugs, should be taken as directed by a doctor when violations have already occurred in one direction or another (hypo or hypervitaminosis).
Sources:
