Spring is the best time to remember vitamins. But not so much about what everyone already knows, but about the many myths that many take for medical facts.
We will not recount the history of the discovery of vitamins and retell how each of them affects many biochemical processes occurring in the body. Let's devote this article to practical issues that everyone knows everything about - what in the field of vitamin therapy both patients and even doctors consider to be true and which in fact is absolutely not true. Let's start with the most important and harmful delusion.
I. Origin
Myth 1. The need for vitamins can be fully met through good nutrition
You can't - for a variety of reasons. First, man too quickly "descended from the monkey." Modern chimpanzees, gorillas and our other relatives fill their belly with a huge amount of plant food all day, while plucked directly from a tree in the rainforest. And the content of vitamins in wild-growing tops and roots is ten times higher than in cultivated ones: the selection of agricultural varieties for thousands of years took place not according to their usefulness, but according to more obvious signs - yield, satiety and resistance to diseases. Hypovitaminosis was hardly the No. 1 problem in the diet of ancient hunters and gatherers, but with the transition to agriculture, our ancestors, having provided themselves with a more reliable and abundant source of calories, began to experience a lack of vitamins, trace elements and other micronutrients (from the word nutricium - nutrition). Back in the 19th century in Japan every year up to 50,000 poor people, who ate mostly peeled rice, died of beriberi - vitamin deficiency B1. Vitamin PP (nicotinic acid) in corn is contained in a bound form, and its precursor, the essential amino acid tryptophan, is in trace amounts, and those who ate only tortillas or hominy got sick and died from pellagra. In the poor countries of Asia, at least a million people a year die and half a million go blind due to the fact that rice does not contain carotenoids - precursors of vitamin A (actually vitamin A is most of all in the liver, caviar and other meat and fish products, and the first a symptom of his hypovitaminosis is a violation of twilight vision, "night blindness"). Vitamin PP (nicotinic acid) in corn is found in a bound form, and its precursor, the essential amino acid tryptophan, is in trace amounts, and those who ate only tortillas or hominy got sick and died from pellagra. In the poor countries of Asia, at least a million people a year die and half a million go blind due to the fact that rice does not contain carotenoids - precursors of vitamin A (actually vitamin A is most of all in the liver, caviar and other meat and fish products, and the first a symptom of his hypovitaminosis is a violation of twilight vision, "night blindness"). Vitamin PP (nicotinic acid) in corn is found in a bound form, and its precursor, the essential amino acid tryptophan, is in trace amounts, and those who ate only tortillas or hominy got sick and died from pellagra. In the poor countries of Asia, at least a million people a year die and half a million go blind due to the fact that rice does not contain carotenoids - precursors of vitamin A (actually vitamin A is most of all in the liver, caviar and other meat and fish products, and the first a symptom of his hypovitaminosis is a violation of twilight vision, "night blindness"). In the poor countries of Asia, at least a million people a year die and half a million go blind due to the fact that rice does not contain carotenoids - precursors of vitamin A (actually vitamin A is most of all in the liver, caviar and other meat and fish products, and the first a symptom of his hypovitaminosis is a violation of twilight vision, "night blindness"). In the poor countries of Asia, at least a million people a year die and half a million go blind due to the fact that rice does not contain carotenoids - precursors of vitamin A (actually vitamin A is most of all in the liver, caviar and other meat and fish products, and the first a symptom of his hypovitaminosis is a violation of twilight vision, "night blindness").
Moderate and even pronounced hypovitaminosis in Russia is present in no less than three quarters of the population. A close problem is dysmicroelementosis, an excess of some and a lack of other trace elements. For example, a moderately pronounced iodine deficiency is a ubiquitous phenomenon, even in coastal areas. Cretinism (alas, only as a disease caused by a lack of iodine in water and food) now does not occur, but, according to some reports, a lack of iodine reduces the intelligence quotient by about 15%. And it certainly leads to an increase in the likelihood of thyroid diseases.
A soldier of the pre-revolutionary Russian army, with a daily energy expenditure of 5000-6000 kcal, was supposed to have a daily allowance, including, among other things, three pounds of black bread and a pound of meat. One and a half to two thousand kilocalories, which is enough for a day of sedentary work and lying down, guarantee you a shortage of about 50% of the norm of about half of the known vitamins. Especially in the case when the calories are obtained from refined, frozen, sterilized products, etc. And even with the most balanced, high-calorie and "natural" diet, the lack of some vitamins in the diet can reach 30% of the norm. So take a multivitamin - 365 tablets a year.
Myth 2. Synthetic vitamins are inferior to natural ones
Many vitamins are extracted from natural raw materials, like PP from citrus peel or like B12 from the culture of the same bacteria that synthesize it in the intestines. In natural sources, vitamins are hidden behind the cell walls and are associated with proteins, the coenzymes of which they are, and how much you absorb and how much will be lost depends on many factors: for example, fat-soluble carotenoids are an order of magnitude more fully absorbed from carrots, finely grated and stewed with emulsified fat is sour cream, and vitamin C, on the contrary, decomposes quickly when heated. By the way, you knowthat when natural rosehip syrup is evaporated, vitamin C is completely destroyed and only at the last stage of preparation is synthetic ascorbic acid added to it? In a pharmacy, nothing happens with vitamins until the end of the shelf life (and in fact, for several more years), and in vegetables and fruits, their content decreases with each month of storage, and even more so during cooking. And after cooking, even in the refrigerator, it is even faster: in the sliced salad after a few hours, vitamins become several times less. Most vitamins in natural sources are present in the form of a number of substances similar in structure, but different in effectiveness. Pharmacy preparations contain those variants of molecules of vitamins and organic compounds of microelements that are easier to digest and act most effectively. Vitamins,obtained by means of chemical synthesis (like vitamin C, which is made both bio-technological and purely chemical means), do not differ from natural ones: in structure they are simple molecules, and there simply cannot be any "vital force" in them.
II. Dosage
Myth 1. Horse doses of vitamin … help from …
In the medical literature, articles on this topic appear regularly, but after 10-20 years, when scattered studies on different population groups, with different dosages, etc., accumulate enough to conduct a meta-analysis, it turns out that this is another myth. Usually the results of such an analysis boil down to the following: yes, a lack of this vitamin (or other micronutrient) is associated with a greater frequency and / or severity of this disease (most often - with one or more forms of cancer), but the dose is 2-5 times exceeding the physiological norm, does not affect either the incidence rate or the course of the disease, and the optimal dosage is approximately the one indicated in all reference books.
Myth 2. A gram of ascorbic acid per day protects against colds and in general from everything in the world
Twice the Nobel laureates are also mistaken: hyper- and megadoses of vitamin C (up to 1 and even 5 g per day at a rate of 50 mg), which became fashionable with the suggestion of Linus Pauling,, as it turned out many years ago, do not benefit ordinary citizens. A decrease in the incidence (by several percent) and the duration of acute respiratory infections (less than one day) compared with the control group taking the usual amount of ascorbic acid was found only in a few studies - in skiers and special forces who trained in the winter in the North. But there will be no big harm from megadoses of vitamin C, except perhaps hypovitaminosis B12 or kidney stones, and even then only for a few of the most zealous and fanatical supporters of ascorbinization of the body.
Myth 3. Better lack of vitamins than too much
To sort out vitamins, you need to try very hard. Of course, there are exceptions, especially for the minerals and trace elements that are part of most multivitamin complexes: those who eat a portion of cottage cheese every day do not need an additional intake of calcium, and those who work in the galvanic shop do not need chromium, zinc and nickel. In some areas, water, soil and, ultimately, in the organisms of people living there, there are excess amounts of fluorine, iron, selenium and other trace elements, and even lead, aluminum and other substances, the benefits of which are unknown, and the harm is beyond doubt. But the composition of multivitamin tablets is usually selected sothat in the overwhelming majority of cases they cover the micronutrient deficiency of the average consumer and guarantee that no serious overdose is possible, even with daily and long-term intake in addition to the usual diet of several tablets.
In most cases, hypervitaminosis occurs with prolonged consumption of vitamins (and only fat-soluble vitamins that accumulate in the body) in doses that are orders of magnitude higher than the norm. Most often, and then extremely rarely, this is found in the practice of pediatricians: if from a great mind, instead of one drop a week, give a newborn a teaspoon of vitamin D a day … The rest is on the verge of jokes: for example, there is a story about how almost All the housewives in the village bought a vitamin D solution stolen from a poultry farm under the guise of sunflower oil. Or - they say, it happened - after reading all sorts of nonsense about the benefits of carotenoids, "preventing cancer", people began to drink liters of carrot juice a day, and some of this not only turned yellow, but drank themselves to death. It is impossible to assimilate more than a maximum of vitamins determined by nature through the gastrointestinal tract with a single intake: at each stage of absorption into the intestinal epithelium, transfer to the blood, and from it to tissues and cells, transport proteins and receptors on the cell surface are required, the number of which is strictly limited. But just in case, many firms pack vitamins in jars with "child-resistant" lids - so that the baby does not gobble up his mother's three-month norm at a time.
III. Side effects
Myth 1. Vitamins cause allergies
An allergy can develop to a drug that you have taken before and part of the molecule of which is similar in structure to one of the vitamins. But even in this case, an allergic reaction can manifest itself only with intramuscular or intravenous administration of this vitamin, and not after taking one tablet after a meal. Sometimes the colorants, fillers and flavors included in the tablets can cause allergies.
In this case, it is recommended to switch to vitamins from another company - perhaps they do not contain this particular component.
Myth 2. With the constant intake of vitamins, addiction develops to them
Addiction to air, water, as well as fats, proteins and carbohydrates does not scare anyone. You will not get more than the amount for which the mechanisms of assimilation of vitamins are designed - if you do not take doses for several months or even years, orders of magnitude more are required. And the so-called withdrawal syndrome is not typical for vitamins: after stopping their intake, the body simply returns to a state of hypovitaminosis.
Myth 3. People who do not take vitamins feel great
Yes - about the same as a tree growing on a rock or in a swamp feels great. Symptoms of mild polyhypovitaminosis such as general weakness and lethargy are difficult to notice. It is also difficult to guess that dry skin and brittle hair should be treated not with creams and shampoos, but with the intake of vitamin A and stewed carrots, that sleep disorders, irritability or seborrheic dermatitis and acne are not signs of neurosis or hormonal imbalance, but a lack of group vitamins B. Severe hypo- and avitaminosis are most often secondary, caused by some kind of disease in which the normal absorption of vitamins is disrupted. (And vice versa: gastritis and anemia - a violation of the hematopoietic function, visible to the naked eye by the cyanosis of the lips - can be both a consequence and a cause of vitamin B12 deficiency and / or iron deficiency.) And the connection between hypovitaminosis and increased morbidity, up to a higher frequency of fractures with a lack of vitamin D and calcium or an increased incidence of prostate cancer with a lack of vitamin E and selenium, is noticeable only in the statistical analysis of large samples - thousands and even hundreds of thousands of people, and often - when observed for several years.
Myth 4. Vitamins and minerals interfere with the assimilation of each other
This point of view is especially actively defended by manufacturers and sellers of various vitamin and mineral complexes for separate intake. And in confirmation, they cite the data of experiments in which one of the antagonists entered the body in the usual amount, and the other in tenfold large doses (above we mentioned hypovitaminosis B12 as a result of ascorbic addiction). The opinions of experts about the advisability of dividing the usual daily dose of vitamins and minerals into 2-3 tablets differ exactly the opposite.
Myth 5. "These" vitamins are better than "Tech"
Usually, multivitamin preparations contain at least 11 of the 13 vitamins known to science and about the same amount of mineral elements, each - from 50 to 150% of the daily value: there are fewer components, the lack of which is extremely rare, and substances that are especially useful for all or some groups of the population - just in case, more. The norms in different countries differ, including depending on the composition of the traditional diet, but not much, so you can ignore who set this norm: the American FDA, the WHO European Bureau, or the USSR People's Commissariat of Health. In the preparations of the same company, specially designed for pregnant and lactating women, the elderly, athletes, smokers, etc., the amount of individual substances can differ several times. For children, from infants to adolescents, the optimal dosages are also selected. For the rest, as they once said in a commercial, all are the same! But if the packaging of "a unique natural food supplement from environmentally friendly raw materials" does not indicate the percentage of the recommended norm or does not say at all how many milli- and micrograms or international units (IU) one serving contains, this is a reason to think.
Myth 6. The newest legend
A year ago, the media around the world spread the news: Swedish scientists have proven that vitamin supplements kill people! Taking antioxidants on average increases the mortality rate by 5% !!! Separately, vitamin E - by 4%, beta-carotene - by 7%, vitamin A - by 16% !!! And even more - for sure, many data on the dangers of vitamins remain unpublished!
It is very easy to confuse cause and effect in a formal approach to mathematical analysis of data, and the results of this study have caused a wave of criticism. From the equations of regression and correlations obtained by the authors of the sensational study (Bjelakovic et al., JAMA, 2007), we can draw the opposite and more plausible conclusion: more general tonics are taken by older people who feel worse, get sick more and, accordingly, are more likely to die. But the next legend will surely walk in the media and public consciousness as long as other myths about vitamins.
Alexander Chubenko