In school we learned that vitamins can be a means of preventing a number of diseases.
But should I make them a panacea? And how accurate is the current craze vitamin complexes?
Deeds of days gone
Nice to know that the key research leading to the understanding of the role of vitamins, were carried out by Russian scientists. In 1880 N. And.Lunin during experimental work has established that foods are unknown at the time of the substances essential for life. When mice were fed whole milk, they grew well and was not sick. But if the quality of the food they were given a mixture of the main components of milk - casein, fat, lactose, salt, and water began to hurt and quickly died.
The term "vitamins" (vita - life, lat.) only appeared in 1912. For a long time, these biologically active substances remained exclusively in medical management, but with the 60-ies of the last century began, this vitamin revolution.
Today we are surrounded by a variety of vitamin products, and they can be registered both as drugs and as biologically active food supplements - dietary Supplements (dietary supplements on American and European terminology).
Size matters
Pharmaceutical companies and manufacturers of dietary supplements have long had to order Zurab Tsereteli's monument to the Linus Pauling. Of pure gold. The size of the monument to Peter I. Because the winner of two Nobel prizes, a brilliant chemist and scientist-encyclopedist opened for them a gold mine.
"The appropriate amount of vitamin C prevents colds," said Pauling. The "corresponding" he believed dose, hundreds, or even thousands of times exceeding the recommended daily. So vitamins escaped from the hands of the doctors and rushed closer to the consumers in supermarkets, consumer departments, pharmacies and other easily accessible places.
But brilliant scientist was wrong, he built his entire theory on the initially incorrect postulate. The most interesting thing learned in this Institute... Linus Pauling, who was created specifically for the development of the ideas of Nobel laureate. There under the guidance of the Director of the Institute, Professor Balsa fry collected data on hundreds of studies on thousands of volunteers worldwide. The conclusion reached by scientists who shocked them. Indeed, the Hyper doses of ascorbic acid about 20% reduce the duration of colds and several mitigate its symptoms. But only if you're already sick. But preventive effect from them no.
About the lack of preventive effect is evidenced by a Cochrane review (which is the Cochrane library and performed in accordance with all requirements of evidence-based medicine) Dr. R. M. Douglas and co-authors (included 11.350 patients), amended for the last time in may 2007. By the way, the data on the therapeutic effects of vitamin C these authors differ from the results of Pauling Institute. In the Cochrane review highlights that not only preventive and therapeutic effect of vitamin C pack, so compared with placebo not mentioned.
So vitamin C is not a guarantee against cold, though kilograms eat it. However, the weight still does not work - it is established that long-term use of large doses of ascorbic acid may cause anxiety, insomnia, unmotivated feeling of heat, inhibition of the synthesis of insulin, adverse effects on the kidneys and high blood pressure.
And a small comment about Pauling. Some, shall we say, unscrupulous sellers multivitamin complexes (especially registered as Supplements) are "crushed authority, arguing that Linus Pauling was awarded the Nobel prize for the discovery of the effect of large doses of vitamin C. This is not the case. Not so. The Nobel prize in chemistry scientist received in 1954 "For the study of the nature of the chemical bond and its application to the explanation of the structure of complex molecules". And his second Nobel prize (1963) was the peace prize. But ascorbic acid in doses much higher than recommended, Pauling became interested only in the late 1960s-X.
Longer does not mean better
Unfortunately, Pauling were hundreds of followers, who developed his theory and made it not only ascorbico, but also on all the vitamins in General. This is especially true of "neighbors" vitamin C pack, so in a very fashionable group of antioxidants - substances that protect cells from the damaging effects of free radicals. It is the antioxidants and free-radical theory of aging gave a new stimulus was extinguished race vitamin arms. After all, to be young and healthy I want for as long as possible.
Talking about the vitamins a and E. Both of these vitamin is fat-soluble and therefore can accumulate in the body and influence the condition of its organs and systems. And not always favorably. The proof is quite a scandal with clinical trials of beta-carotene, the precursor of vitamin.
American researchers studied the effect of vitamin supplementation with beta carotene on cancer risks in smokers. In particular, it was assumed that lung cancer in humans, protected beta-carotene, will develop much less.
After eight years of follow-up for 15 thousands of smokers who took beta-carotene, the study had to be stopped. The results threw scientists in shock: in the experimental group frequency of cancer has not decreased, it has increased by as much as 18%.
A year and a half was stopped another similar study, capturing 28 percent jump tumors in the lungs. Still no one could explain why this happened. But one thing is clear - smokers contraindicated vitamins and minerals with beta-carotene. And others should watch, if the dose of this substance in the product exceeds the recommended daily.
However, this is not all the misadventures of vitamin A. Swedish scientists interested in the too great frequency of osteoporosis among the population. Having studied history more than 66 thousand women over the age of forty years, the researchers concluded that the reason lies in the diet. More precisely, the high content of vitamin a in traditional Scandinavian foods - fatty fish (herring, salmon), cod liver oil, and milk (Sweden additionally enriched skim milk vitamin a). While the Swedes still keen and vitamin preparations.
Only 1, 5 milligrams of vitamin a per day, according to the data obtained, 10% reduced bone density and a two times increased risk of fracture. But this is only a two-fold excess of the recommended daily dose. Later the results of this study were confirmed and American scientists. In addition, it was found that the excessive intake of retinol increases the need for vitamins C and B1, intensify the symptoms of vitamin D deficiency, and sometimes there is a specific liver disease.
It is also worth mentioning vitamin a during pregnancy. There is data on the teratogenic effect (i.e. the formation of birth defects in the fetus) his hyperdoc. This does not mean that you should not take vitamins that are assigned to the expectant mother a doctor. And foods rich in vitamin a, to refuse shouldn't. Not only need to deal with self-diagnosis and self-treatment and self-initiative to take any additional medications that contain this vitamin. Again he refers to fat-soluble and has the ability to accumulate in the body (mainly in the liver).
Experts still can't exactly answer - what is the dose of vitamin a (higher is recommended) can be considered safe.
The situation with vitamin E is slightly better. It is known that the abuse of this substance can lead to increased blood pressure.
So antioxidants thing, of course, fashionable, but when the excessive and uncontrolled use of not only useless, but, at the confluence of a number of circumstances, dangerous.
In General, as with any powerful biochemical substance, the vitamins can be not only medicine, but also poison. The difference, as it often happens in medicine, only in the dosage.
To eat or not?
One of the main arguments of the supporters of the constant ingestion of large amounts of vitamins - debituminization modern food. Even if a person eats balanced and physically active, vitamins he is still missing. This is due to the fact that, indeed, fresh food in our diet is becoming less and less dominated by frozen, canned, concentrated and processed in other ways. This is done, firstly, to increase shelf life, and secondly, to reduce the time for preparation.
Another argument "kruglosutochno": on average, nine months of the year the Europeans eat vegetables grown in greenhouses or after a long storage period. Such products have significantly lower levels of vitamins than vegetables from the open ground.
In addition, after three days of food storage in the refrigerator lost about 30% of vitamin C. At room temperature, the average is about 50%. And if a peeled potato to put in water, ascorbico from it will go away in a few hours. If we talk about the heat treatment of products, in this case it is lost from 25% to 90-100% of the remaining vitamins. Yes, and in the light of the vitamins are destroyed.
In addition, the energy demands of the modern man are significantly reduced, and the need for vitamins produced by millions of years of evolution, have remained the same.
From the foregoing, the conclusion about the necessity of continuous intake of vitamin-mineral complexes, containing an impressive dose of active substances.
All this, of course, true, but only partly. Yes, indeed, if you eat one fast food, earn hypovitaminosis is not so difficult. And, really, need medication to compensate vitamin deficiency. There are seasonal fluctuations in the content of vitamins in vegetables and fruits is also true.
But indiscriminately to say about the lack of vitamins is not worth it. Because you can store food in the refrigerator can not three days, and one. Or bring with market fresh greens-cucumbers-tomatoes and immediately make a salad.
Again, one must consider the additional food fortification. This concerns, first of all, fortified juices, cereals and a variety of dairy products. For the sake of scientific interest, the author has studied the packaging first arm of fruit juice. If you believe the information on the label, a liter of the drink covers 70% of the daily requirements for vitamins E, B1 and B6 and 60% of the daily requirement of vitamin C.
To drink or not to drink?
Most researchers tend to believe that after all the vitamins you should take. Even if you have no reason for it other than "I want". But in the case of fortification, as in other good deeds is better to do without fanaticism and to consider some points.
1. Residential vitamins are only needed in the case of a proven weight on a particular micronutrient this particular person. Usually sufficient preventive courses, say, once a quarter for 3-4 weeks.
2. Do not exceed the recommended daily dose, especially fat-soluble vitamins. Therefore, carefully study the composition of selected vitamin and mineral complex, especially the column "% of the recommended daily dose". If there are numbers between 150 and above will reschedule this drug should be used in therapeutic, but not in the preventive purposes. However, in the U.S., according to eyewitnesses, in the free market there are jars of 500 capsules of vitamin E, in each capsule which contains 1113% of the daily dose.
3. Before taking vitamins, it is advisable to consult a physician. It will help to determine what substances are needed by your body, and in what form they need to enter into the diet.
However, to determine vitamin situation the doctor will be more focus on clinical manifestations, and they are pronounced only when avitaminosis. Suspect same hypovitaminosis of symptoms is almost impossible. The most accurate answer can be given blood tests, but specialized testing in Russia so far available only in clinical laboratories and a wide distribution has not yet received.
Chemistry and life
Synthetic analogues of vitamins need to comply not only with the chemical formula, and spatial structure.
Natural foods contain the desired isomer, but the chemical production initially obtained motley mixture that you want to clear and select the right vitamins. This requires high-tech and expensive equipment. Unfortunately, not all domestic (and not at all foreign enterprises it is.
If all requirements are met and coincides not only chemical, but also the spatial structure, the body is deeply indifferent, where to get vitamins.
Keep in mind that vitamin deficiencies are often blamed chronic fatigue, drowsiness, apathy - although typical they are for a number of diseases. And the doctor's advice "drink vitamins" may be only a polite form of expression, "go away, you don't have any pathology, you already from ears to toe examined, get these hypochondriacs, my strength isn't there anymore".
4. Spring prophylactic course can be done almost all (with very rare exception). These rare exceptions are sometimes referred people with allergies vitamins". Now, in the vast majority of cases, an allergic reaction occurs not on the active component, and all sorts of flavors, colors, preservatives and other improvers appearance, taste and shelf life. These people can recommend just changing the drug.
What vitamins to take? The choice is huge, drugstore shelves are filled with dozens of colorful and diverse boxes. It is advisable to use products large and well-reputed pharmaceutical companies.
And here is what not to do, is use of vitamin-mineral complexes, registered as a dietary Supplement.
First, Supplements are not checked for compliance with the recipes - both qualitative and quantitative. Important for regulators to Supplement no poisons, drugs and other toxic substances.
Secondly, in most cases, neither of which the balance of the composition can not speak. And, most worryingly, no one responsible for it won't bear you bought is not a medicine, and biologically active food Supplement. What, incidentally, should be written on the box. Turn in the pharmacy packaging, look, whether this information is in small letters on the selected drug. In doubt, ask the pharmacist behind the counter.
Oh, and don't forget that normal food vitamins are also found. And vegetables-fruit-milk-meat - not the worst of the possible sources necessary for our body of nutrients.
Author:
Volgin A.
Source:
MedPortal.ru
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