home Audience 6 Vitamin D: the body's solar friend. Vitamin D: how to replace the sun

Vitamin D: the body's solar friend. Vitamin D: how to replace the sun

There are many factors that influence how much vitamin D you can get from sun exposure. Full list consists of 12 points:

Now let's look at them in more detail.

Latitude and height

Highest intensity sunlight, of course, at the equator. The sun is located directly overhead and UV radiation reaches the Earth along the shortest path. The further you are from the equator, the more distance sunlight must travel through the Earth's atmosphere before it hits your skin. UV radiation is about four times stronger at the equator than in the Arctic and Antarctic.
According to the intensity UV radiation The time it takes for your skin to produce vitamin D will depend.
To understand how much time you need to spend in the sun, you first need to determine your geographical coordinates. This can be done using GPS (can be built into your cellular telephone) or use Google Earth.
For example, Moscow has coordinates 55°45’N.

If your location is between 0 and 10 degrees north or south latitude, then you have intense sunlight throughout the day (and especially during the few hours before and after noon) throughout the year.
If you live at a latitude of 10 to 30 degrees, then the sun is especially intense in the middle of the day (from 10 to 14 hours). After dawn and before sunset it is much softer and the time to obtain vitamin D at this time will take much more than during the day. High intensity of solar radiation occurs in summer period. In other seasons, it decreases and it will take more time to produce a sufficient amount of vitamin D.
At latitudes between 30 and 50 degrees, sunlight is intense during the summer and only at daytime hours(from 10 to 14 o'clock in the afternoon). In the spring and autumn, it takes a lot of time to obtain vitamin D from sunlight and the level will be minimal.
If you live at a latitude of 50 degrees, then the sun in this area is active only in the summer and only during the daytime. What saves the situation is that the majority of people living at these latitudes are light-skinned and because of this they are more susceptible to sunlight. People living in these latitudes with dark color skin, most likely do not receive enough vitamin D even in the summer.
UV radiation also depends on altitude. Because at higher altitudes, sunlight has to overcome a smaller layer of atmosphere. And the atmosphere, as is known, has the ability to absorb sunlight.
Those. The higher your area is above sea level, the less time you need for a sufficient amount of vitamin D to form in your skin.
Season
The season affects the angle at which sunlight hits the ground and thereby determines the amount of UVB radiation that will be available to your skin. The season during which sunlight will be active depends on your latitude.
For latitudes above 35 degrees, between November and March, the skin produces virtually no vitamin D, regardless of the time you spend in the sun.
Before the beginning summer season It would be a good idea to gradually prepare the skin starting in spring. And if this is possible, then you should start sunbathing in early spring with a minimum amount of clothing and, naturally, around noon.

Times of Day

The weather forecast usually includes a UV index, which characterizes the level of solar UV radiation at certain hours. The higher the rating, the more likely you are to get sunburned. But the body's ability to produce more vitamin D increases as this index increases. To obtain the optimal D level with a UV index of more than 8, only a few minutes of exposure to the sun is required. If the UV index is less than or equal to 2, then vitamin D is not produced in the skin.
For some latitudes, the only time when vitamin D will be produced is from 10 a.m. to 2 p.m. At this time, the UV index for a given latitude is maximum.
You can view the UV index on the Internet on a website with the current weather.

Usually the media recommend not going out into the open sun at midday so as not to get skin cancer. But for Moscow residents this is the only possible time Replenish vitamin D stores from sunlight. What to do in this case?
In this case, you can seek help from an exposure calculator (the amount of time you can safely spend in the open sun).
There are even electronic devices for this that will calculate everything as accurately as possible. Or you can use a calculator from the Internet, which will also calculate the time you need to spend in the sun to get optimal dose vitamin D.
And oddly enough, the middle of the day is the safest time - the time you will need to spend in the sun is minimal. During this time, the skin will not have time to burn, but will have a slightly pink tint. During this time, your skin will produce a maximum amount of vitamin D of 20,000 IU. Mother nature simply will not allow you to produce more and the excess vitamin will be destroyed. Continued exposure to the sun may be harmful to your skin.

Air pollution

Air pollution can block UVB rays, which will prevent you from producing vitamin D.

Cloudiness

The more clouds in the sky, the less ultraviolet radiation reaches the surface of the Earth. However, UV rays can penetrate clouds, especially light clouds.

Sunscreens and clothing

If you have to spend a long time in the open sun, then sunscreen and clothing are a necessity for you. But at the same time, these products deprive you of the opportunity to get optimal levels of vitamin D from sunlight.
A sunscreen with SPF 8 reduces your skin's potential production of vitamin D by up to 92 percent; a sunscreen with SPF 15 reduces production by 99 percent. Therefore, before applying cream, spend some time under the sun without any cream.
Melanin, skin color and vitamin D
The darker your skin, the less vitamin D she is capable of producing. It's strange, but it's true. The pigment melanin is responsible for skin color. And it is melanin that blocks UVB rays. And when people did not have the opportunity to change the continent of residence, there were no problems with this. For example, when people with dark skin lived close to the equator, they received enough sunlight to produce vitamin D, even though most of the UV rays were blocked by the skin's melanin. When they moved to northern latitudes, they often lacked the intensity of solar radiation.

In 1975, Thomas Fitzpatrick, MD, of Harvard, developed a skin type classification system based on how the skin reacts to the sun. According to this classification, there are six skin types:

Type 1 Skin always burns in the sun, never tans and is very light
Type 2 The skin always burns in the sun, sometimes tans and is quite light.
Skin type Z sometimes burns in the sun, gradually tans and is considered medium in tone.
Type 4 Skin rarely burns in the sun, always tans and has an olive tone.
Type 5 Skin rarely burns in the sun, always tans, and looks dark.
Type 6 Skin never gets sunburned, always tans and looks very dark or black.

The lighter the skin, the less melanin it contains and the less time it takes to produce vitamin D.

Age

With age, the skin produces less and less provitamin D and therefore the skin is able to produce less and less vitamin D.

Body mass

People who are overweight are much more likely to suffer from vitamin D deficiency. The fact is that vitamin D is fat-soluble vitamin, are therefore too well absorbed by the fat mass, making it less available for use in other tissues and organs of the body.

Amount of clothing covering the body

Clothing prevents sunlight from reaching your skin. Dermatologists and oncologists recommend wearing Sunglasses, hats and long-sleeved shirts to provide maximum skin protection and prevent cancer. In addition, there is national clothing that covers almost the entire body. For example, among women and children in Saudi Arabia Rickets, osteomalacia and simply vitamin D deficiency are very common.
It turns out that completely depriving yourself of sunlight, covering yourself with clothes from head to toe and without taking vitamin supplements, no less dangerous to health.
Therefore, use UV radiation calculators and periodically spend time in the sun with a minimum amount of clothing.

Washing with soap

When I came across this information, I was very surprised. But it turns out that using soap prevents vitamin D from being absorbed. It takes up to 48 hours for vitamin D to enter the bloodstream. And up to 48 hours, you can easily wash it off by rubbing your skin with a washcloth and soap...
Of course, no one is asking you to cancel your daily hygiene procedures. But, unfortunately for marketers, shower gel for the whole body will have to be cancelled. You also need to remember the rule that you should wash with detergents(soap, gel, etc.) you can only use your armpits, groin, and hands, of course. Sweat, dust and dirt are easily washed away warm water no soap.

The conclusion from all this is simple: the sun is the most important source of vitamin D. But there are situations when it cannot be the only source of vitamin D. If you constantly sit in an office in the center of Moscow or walk for many hours in Moscow in the winter, then vitamin D You can only get it from vitamin supplements.

Vitamin D plays important role in the functioning of the immune, nervous, cardiovascular and other systems of the body.

Irina Zhukova, Ph.D., dermatocosmetologist

For a long time, vitamin D was “in the shadows” and was considered a drug for the prevention of rickets for children, as well as for strengthening bone tissue in old age. IN last years Vitamin D in combination with calcium is actively promoted for strengthening bone tissue. But clinical and experimental data in recent years have proven widest spectrum its effects on the human body. Vitamin D is involved in the regulation of fat and carbohydrate metabolism substances, maintaining normal blood pressure, preventing the so-called metabolic syndrome. The role of vitamin D in immune reactions, prevention oncological diseases and other aspects of human life.

In this regard, large-scale studies have been carried out to assess the vitamin D content in the modern human body. And the results of these studies turned out to be very sad.

Humans get vitamin D from two sources: animals and plant products containing different shapes vitamin D, as well as from the skin, where vitamin D is formed in the upper layers of the skin under the influence of UVB spectrum B with a wavelength of 270-315 nm.

The foods richest in vitamin D are fatty varieties fish and canned fish, butter and eggs. Vitamin D is not destroyed during food storage and cooking and also has high bioavailability, but its consumption with food is usually so small that it does not satisfy the body's need. And the main source is its synthesis in the skin under the influence of ultraviolet radiation. The production of provitamin D in the skin depends on the geography of the place, time of day, ecology and atmospheric cloudiness. The required wavelength is present in the solar spectrum characteristic of the tropics; for spring and summer sun in countries with temperate climates, and is not found in arctic latitudes. The formation of vitamin D almost completely stops in the morning and evening, throughout the day during the winter months at latitudes above and below 35 degrees, as well as in a crowded or cloudy atmosphere. The UVB spectrum of type B required for full synthesis is characteristic of the tropics, and among Russian residents, the formation of vitamin D in the skin occurs within approximately 7 months at the latitude of Sochi, 4 in Moscow, less than 3 (May-June) months in St. Petersburg.

30 minutes– during this time in the summer, a fair-skinned person receives an amount of vitamin D equal to 227 chicken eggs or half a kilo of cod liver.

6 months The “winter of vitamin D” continues for residents of Russia, Northern Europe and Canada.

In addition, other factors influence the production of vitamin D: age, the degree of “openness” of the body, skin color and the severity of subcutaneous fat. Vitamin D production is reduced in the elderly and obese. The skin pigment melanin, which is formed during the tanning process, is a natural sun protection factor, so dark-skinned people need 3-6 times high dose sun exposure to produce the same amount of vitamin D compared to fair-skinned people. In addition, ordinary glass in houses and cars, clothing and cosmetics with sun protection factors prevent the action of UVB, even in summer.

But excessive inmolation causes the so-called “skin photoaging”, and also stimulates the development malignant neoplasms. Therefore, doctors strongly recommend avoiding excessive sunbathing and carefully protecting your skin from the sun. And the result of this was, along with the positive phenomenon - the “unfashionable image” of tanning, that people who avoid the sun have increased risk development of hypovitaminosis throughout the year. According to leading world experts, about a billion people on Earth, children and adults, are deficient in vitamin D.

SO WHY DO WE NEED VITAMIN D?

Vitamin D is most important for normal functioning bone tissue. The role of calcium in bone formation is beyond doubt, but, unfortunately, very often even experts forget that with vitamin D deficiency, normal calcium metabolism is almost impossible. Consumption of even large amounts of calcium as part of dietary supplements or medications for hypovitaminosis D not only does not lead to an improvement in the condition of bone tissue, but, on the contrary, may be accompanied by the appearance of kidney stones and calcium deposition in the body.

According to statistics, 30% of older people fall once a year, 10% of those who fall have a hip fracture, and every fourth patient with a hip fracture dies within a year of the fracture. Due to the progressive “aging” of the population, especially in developed countries, this problem is becoming enormous. social significance. Of no small importance are various injuries and among younger people - on slippery sidewalks, during classes various types sports, etc. Regular periodic intake of vitamin D leads to a reduction in the number of fractures by more than 30%. Moreover, there is not only a decrease in the number of fractures, but (and this sounds fantastic at first glance!) a decrease in the number of falls. Normalization of vitamin D levels leads to improved neuromuscular transmission and muscle function, which leads to human body automatically reacts faster to changes in position in space and manages to maintain balance. In addition, vitamin D prevents the loss of muscle mass and strength that is characteristic of older people.

Next important aspect The effect of vitamin D on the human body is its effect on the so-called “metabolic syndrome”, the main manifestations of which are: lipid metabolism disorders, excess weight, arterial hypertension, diabetes 2 types. Metabolic syndrome and the terrible diseases that result from it, such as heart attack and stroke, are considered the number one cause of death for modern people. Positive influence vitamin D on various aspects of the formation of metabolic syndrome is confirmed by the results of numerous studies conducted in accordance with all the rules of evidence-based medicine.

Vitamin D provides the human body with complete immune defense. It is believed that hypovitaminosis D in winter may be one of the main reasons determining the seasonality of influenza and ARVI. The active form of vitamin D is one of the effective regulators of the inflammatory process, which is associated with its positive action for chronic inflammatory processes V osteoarticular system. Vitamin D is also believed to be an unexplored substance that helps reduce pain. A pronounced analgesic effect (more than 90% of patients) from taking vitamin D was noted in patients of all ages with pain in the back, joints, etc.

Doctors also paid attention to vitamin D aesthetic medicine. Vitamin D has a regulating effect on the functioning of the upper layers of the skin and protects it from photoaging. Vitamin D improves condition and function muscular system due to stimulation of synthesis muscle fibers. Normalizing its level leads to improved neuromuscular transmission and muscle function, which has a positive effect on the condition of the face and body, and allows you to fight flabby muscles of the arms, thighs, and abdomen. In addition, taking vitamin D prevents a decrease in the absolute amount with age. muscle mass, that is, necessary for maintaining muscle strength, endurance and youthful body contours. Nutritionists have concluded that vitamin D not only helps the body absorb calcium and strengthen bones, but also regulates the formation of adipose tissue.

Women who were found to be deficient in vitamin D weighed on average 8-9 kg more than those who had sufficient amounts of this vitamin. Why? Doctors suggest: either the vitamin slows down the process of formation of fat cells, or, conversely, fat cells block vitamin D, preventing its absorption by the body.

Thus, it can be concluded that vitamin D plays an important role in maintaining proper operation immune, nervous, cardiovascular and many other systems of the body. Low levels of vitamin D in blood plasma are associated with the development of diseases such as osteoporosis, arterial hypertension, diabetes mellitus type 1 and 2, malignant neoplasms, infectious diseases, periodontal disease.

The need for vitamin D is increased with a lack of ultraviolet radiation: in people living at high latitudes, residents of regions with increased air pollution, working night shifts, or simply leading night look life that is not outdoors. Intestinal and liver disorders and gall bladder dysfunction negatively affect the absorption of vitamin D. In pregnant and lactating women, the need for vitamin D increases, because Additional amounts are needed to prevent rickets in children.

How to modern man fight hypovitaminosis D? The main source of vitamin D is dietary intake in traditional and fortified foods or biologically active additives to food.

There are several pharmaceutical forms of vitamin D preparations. The issues of duration of courses of administration and optimal dosages are currently being discussed by experts. In accordance with the “Norms” adopted in 2008 physiological needs”, children and people of working age should receive 10 mcg (400 IU) of vitamin D per day, pregnant and lactating women - 12.5 mcg (500 IU), people over 60 years old - 15 mcg (600 IU).

30% – This is how much the number of fractures decreases with regular vitamin D intake.

10 mcg (400 IU) – This is the generally accepted daily requirement of vitamin D for children and people of working age.

Thus, the pronounced prevalence of hypovitaminosis D throughout the globe and its steady progression have turned the “children's vitamin” into one of the main objects of interest for the rapidly aging population of developed countries. Not in vain modern doctors Vitamin D is called the vitamin of sunshine and longevity.

And in the dark and cold winter months, when there is so little sun and colds and viral diseases wait around every corner, and in hot sunny summers, when it’s so easy to burn in the scorching sun, the most important factor to maintain immunity is high level vitamin D in the body, which directly depends on the amount of ultraviolet radiation received. Numerous studies are now being conducted on this topic, which often refute data that were previously considered indisputable facts and, as a result, recommendations are often given that are directly opposite to those that were given before. You've probably heard some vague advice, such as getting in the sun for "a few minutes every day." But they are too general and vague to be useful. The amount of sun you need to meet your vitamin D needs varies greatly depending on your location, skin type, time of year, time of day, and even atmospheric conditions.
Myths about tanning:
1. Sunbathing is best before 12 noon and after 15 pm.

4. With the help of any solarium you can gain the missing vitamin D in the winter.

1. It is best to sunbathe before 12 noon and after 15 pm.
The optimal time of sun exposure to produce vitamin D is, as far as possible, around midday, approximately between 11:00 am and 3:00 pm.

The fact is that the region of ultraviolet radiation includes waves of different ranges, which are conventionally divided into three groups:

UV-A (UVA) (315–400 nm)

UVB (280–315 nm)

UV-C (UVC) (100–280 nm)

UVA and UVB rays are able to pass through the ozone layer to reach our skin, but they differ significantly when it comes to their individual characteristics.

UVB rays:

Responsible for launching the production of vitamin D in the skin.

They cause sunburn.

Cannot penetrate glass or clothing.

They are active only at certain times of the year and day.

UVA rays

DO NOT trigger vitamin D production in the skin.

Does not cause sunburn.

Penetrate deeper into the skin than UVB rays and therefore cause premature aging, discoloration, and wrinkles.

They are able to penetrate glass and clothing, and are active all day long throughout the year.

Between 11:00 am and 3:00 pm, short periods of sun exposure are sufficient to obtain vitamin D because UVB rays are most intense at this time. But you need to be very careful with the time you spend in the sun. Remember that this exposure is enough for the skin to become slightly pink. For some it will take a few minutes, for others it may be an hour or more, after which it only increases the chances of burning out, which is definitely something you want to avoid. The fact is that the body can only produce a limited amount of vitamin D per day. Once it reaches its limit, further exposure to the sun will only cause harm and damage to the skin.
When the sun goes down to the horizon, much more UVB rays are filtered out than dangerous UVA rays. It is also quite possible that sun exposure at 9 am or 5 pm will reduce vitamin D levels, since there is evidence that UVA destroys it.
So if you want, get out in the sun to optimize vitamin D production and minimize your risk malignant melanoma- the middle of the day is the best and safest time.

2. To maintain the required level of vitamin D in the body, it is enough to expose your hands and face to the sun 2-3 times a week for 5-15 minutes during the summer months.
It is generally accepted that for most people, 15 minutes of exposure to ultraviolet light is enough to produce as much vitamin D in the skin as doctors recommend should be produced daily to maintain health.
However, once you get a tan, you need to spend much more time in the sun. If you have dark skin, then reaching the equilibrium point may take two to six times longer (up to an hour or two), depending on the pigmentation. People with fair skin faces. those living quite far from the equator (for example, in the UK or in the north of the USA, central Russia) need at least three of 20-minute sessions per week, in bright midday sunlight and with a minimum of clothing. A dark-skinned person, of course, must be in the sun much more, and more often, to get the same effect.

This information is just beginning to filter through the media. mass media, so it is important to emphasize this point.

3. When going out in the sun, you should always use sunscreen.
Keep in mind that using sunscreen will largely negate your efforts to metabolize enough vitamin D. It is advisable to ensure that you are not vitamin D deficient before resorting to sunscreen of any kind.

But, if you do need some form of protection when out in the sun for long periods of time, it's best to use light clothing to cover open areas, or look for safer, naturalsunscreens that do not contain petroleum products.
It is also important to remember that if you use the sun or a safe tanning bed to get vitamin D, you need to keep in mind that it takes about 48 hours for vitamin D to completely move from the surface of the skin into the bloodstream, and you can easily wash it off with soap and water. Thus, it makes sense to limit ourselves to the minimum hygiene procedures for at least 48 hours to ensure all vitamin D is absorbed. As strange as it may sound, washing can ruin all your efforts.

4. With the help of any solarium you can gain the missing vitamin D during the winter.
In the winter season, many people use a solarium to prepare their skin for the summer sun, maintain vitamin D levels, avoid winter depression, and simply for beauty. If someone does this in commercial place, remember that it is advisable to ask owners about what kind of lamps they use. There are solariums that use both UVA and UVB radiation in different proportions, and some use only UVA. As noted above, UVB radiation is required to produce vitamin D. In natural sun the ratio of UVA and UVB is approximately 2.5-5.0% UVB, respectively, being in a tanning bed with 5% UVB and 95% UVA is about the same as if you were in bright sunlight in the middle of the day and this enough to get the required dose of UVB radiation, and therefore vitamin D.

In recent years, it has become increasingly clear that even taking into account the recommendations of scientists and doctors, it is not so easy to understand what measures need to be taken in order to. on the one hand, due to excessive caution, do not deprive yourself of what the body needs to maintain good health, and on the other hand, do not harm yourself by neglecting dangerous factors.
Accurate data that OpenWeatherMap supplies to the IT market using the most modern technologies(eg Big Data) can be, and in many areas already is, the basis for products that can help people receive accurate forecasts and recommendations to maintain and protect their health.

A laudable ode to the “sun vitamin”
Vitamin D was discovered in the 20-30s of the last century, and already the first studies showed that it is with a lack of this vitamin that children's body diseases such as rickets, bone curvature and spinal deformity are associated. Currently, a whole group of vitamins D is known - D1, D2, D3, etc. The most important of them are D2 (ergocalciferol) and D3 (cholecalciferol), they are very similar in properties and effects on the body, and they are most often combined one common name– calciferol or vitamin D.

Perhaps someone will have doubts whether we, adults, should attach such importance to the “children’s” vitamin, because the formation time skeletal system It’s been a long time since rickets no longer threatens us. It turns out that vitamin D is not so simple, and it physiological role is not only the regulation of calcium and phosphorus metabolism in the body, which is especially important for a growing organism. Intestinal permeability and other minerals (zinc, iron, cobalt, magnesium) depend on vitamin D. It is indispensable in the fight against work disorders and in the battle against infections, helps the smooth functioning of the heart, regulates the activity of nervous system. Vitamin D is necessary for normal blood clotting, prevents the development of atherosclerosis, and is important for the functioning of thyroid gland and normal blood clotting, helps get rid of many eye diseases. Women who have sufficient levels of vitamin D in their blood are less likely to have benign and malignant tumors breast and ovarian cancer.

So, everyone always needs vitamin D, both in childhood, and in blooming youth, and at the age of elegance, and at sunset. As soon as we stop taking care of supplying our body with this vitamin, problems arise, ranging from aching bones, lower back pain, and ending with fractures, depression, memory impairment, problems with blood pressure, and you never know what else can happen if you neglect the sun vitamin.

And the ways it enters the body are simple:
- externally with food and medications,
- and production by the body under the influence of the sun. Moreover, in the sun, approximately 90% of vitamin D is formed in the body, while about 10% comes from food.

What is also important to note is that vitamin D is fat-soluble; it is not washed out of the body along with liquid, but rather slowly excreted in bile, so it is quite possible to store a certain amount of inactive vitamin D in the liver for several months.

How vitamin D is formed in the skin, or some nuances of sunbathing...
– the main source of vitamin D in the body. Under the sun's rays, vitamin D is formed on the surface of the skin, covered with a thin layer of the cholesterol-like substance ergosterol and sweat, which is then absorbed by the skin, penetrates the bloodstream and ultimately enters the liver, where it is then metabolized into active forms. Moreover, part of the inactive vitamin D is stored in reserve in special liver cells, reticulocytes, which ensures the maintenance of the required level in the body. active forms for several months. In the liver, the process of converting still passive calciferol into active hormone Calcitriol begins and ends in the kidneys, and it is from here that this hormone is sent to fulfill its important mission, controlling the absorption of calcium and phosphorus by the body.

Luckily, our bodies can store vitamin D, so it's important that our skin produces enough vitamin D over the summer to last throughout the rest of the year.

When sunbathing to replenish vitamin D reserves(not for a chocolate tan) there are some things to consider:

- “sunshine” vitamin is formed when sebum located on the surface of the skin is exposed to ultraviolet rays, so you should not wash it off before sunbathing;

Also, don’t rush to accept water procedures immediately after sunbathing, give time for the vitamin to be absorbed into the skin;

They protect us from ultraviolet radiation and at the same time block the skin’s ability to produce vitamin D. Sunbathing without sunscreen for 15-20 minutes in the morning and late afternoon, several times a week, according to experts, it can ensure the synthesis of the required amount of vitamin D;

The activity of the synthesis process is directly dependent on the intensity of irradiation and inversely on the degree of skin pigmentation, that is, the more tanned you are, the lower the skin’s ability to produce vitamin D.

It should also be noted that the skin is able to effectively produce vitamin D under the influence of ultraviolet rays in a clean atmosphere, so walking along city streets, over which a haze of dust and exhaust fumes hangs, is unlikely to promote health and vitamin accumulation.

Give the sun a chance!
So what happens? If we, following the recommendations of dermatologists and oncologists, do not appear outdoors without sunscreen and appropriate clothing, we save ourselves from sunburn, dermatitis, photoaging, malignant neoplasms and at the same time deprive our body of the vitamin D we need so much. What if our skin is already covered with a chocolate tan and burns are not scary for it, we no longer use protective cream so strictly - and our own tan gets in the way of vitamin D synthesis.

Let's try to find a reasonable compromise. Moreover, tanning itself has not been such a prestigious factor in recent years. Thanks to numerous warning publications, excessive tanning these days is no longer perceived as evidence of... healthy image life and social status of its owner, but rather as evidence of some ignorance or frivolous attitude towards one’s own health.

So, our choice is short sunbathing without protective equipment in safe time day (morning, evening), the rest of the time, sunscreen of the required degree of protection, skin care products and good nutrition.

Alternative methods
The second way vitamin D enters our body is through food. The main sources are raw egg yolk, cheese, butter, fish liver (especially cod and halibut), fatty varieties sea fish(herring, mackerel, tuna, mackerel). There are also plant sources vitamin D - parsley, nettle, mushrooms, alfalfa, horsetail - however, its content in them is very small.

Daily requirement in the vitamin that enters the body with food, there are approximately 200 international units /ME/, this is if you are outdoors exposed to sunlight for 30 minutes every day. If sunbathing is not for you, then the norm increases to 1000 IU.

Per 100 g:
- animal liver contains up to 50 IU of vitamin,
- V egg yolk- 25 ME,
- in beef -13 ME,
- in corn oil - 9 ME,
- V butter- up to 35 ME,
- V cow's milk- from 0.3 to 4 IU per 100 ml.

As you can see, even with a nutritious diet, the body’s need for the vitamin is difficult to fully meet through food. A combination of sunlight and right choice menu - the most reliable path solving the problem.

You can also diversify your diet with foods additionally fortified with vitamin D, such as milk, yogurt, breakfast cereals, cookies, and bread. It is only important to take into account that vitamin D is recommended to be taken together with calcium, because its main function is to promote the absorption of calcium by the body and regulate phosphorus-calcium metabolism. If calcium is not supplied with food, then it is taken from the bones, and this is a direct path to the development of osteoporosis. Therefore, milk fortified with vitamin D can be considered healthier than fortified bread.

Well, in the cold season, or when the sun is contraindicated for you, you will have to replenish vitamin D reserves with the help vitamin preparations. When deciding to use vitamin preparations, consult your doctor. You should not take more vitamin D than you need; too much is just as dangerous as too little.

In the meantime, summer reigns, the sun is shining, think about medicines early, spend more time on fresh air, catch the “sunshine vitamin” with all exposed parts of your body, but do not forget about the safety rules.

Greetings, Friends! I hasten to please you about my return from vacation with a new useful article, as well as some news, which I will tell you about at the end of the article. As you may remember, I started a series on the sunshine vitamin.

The last episode included an introductory part where it was told. Today, as promised, I will reveal a secret secret: “Is the sun enough to synthesize vitamin D?”

Why is insolation not enough for vitamin D synthesis?

Previously, it was generally accepted that sunbathing effectively prevents the occurrence and even treatment of rickets in children, not to mention the overall health of the body. In fact, this idea is a general misconception, nothing more than a myth that is passed on from mouth to mouth from the older generation to the younger.

I am not in any way going to dispute that vitamin D is synthesized in the skin when exposed to sunlight and promotes health and longevity. Yes, this is true, but there are some nuances here. And now I will try to prove the fact that the sun alone is not enough for us to maintain health. The material is valid for both adults and children, since every human being needs this hormonal substance, regardless of gender and age.

Russia is a northern country

Agree that most of our vast Motherland is located in a zone of very low insolation. There are cities and villages in which there are only 40-70 in reality sunny days per year. And many may be at work these days.

In addition, in the modern world we travel more and more by car and rarely walk on foot than our ancestors did 100 years ago. A logical chain suggests itself: no sun - no synthesis of vitamin D. For example, below are maps where zones with different solar activity are visible.

Let me remind you that Russia is located north of 40° latitude, and this is obviously a zone of low solar activity. This factor can be considered one of the most important reasons for the widespread deficiency of D-hormone.

If you think that you can accumulate a sufficient amount during the gardening season, then I must disappoint you. The body needs the vitamin every day and although it has a tendency to accumulate, it cannot accumulate in the body like fat in a bear for the entire winter. The supplies are barely enough for a couple of months.

Vitamin D needs more than just sunlight

Many of you know that the ultraviolet spectrum of sunlight is divided into 3 fractions: UV-A, UV-B and UV-C. For the synthesis of vitamin D, only the UV-B fraction is very important, which 80% does not reach the ground and is retained by the ozone layer.

It has also been observed that not all regions of the country have the same level of surface UVB rays. And again, if there are no UV-B rays, then there is no synthesis of vitamin D in the skin.

Sunbathing time

Everything you know Golden Rule that you need to sunbathe in the morning and in the late afternoon. But unfortunately, it is at this time that the least amount of UV-B rays reaches the ground. When you run from the beach for a lunch siesta, you miss ultraviolet waves, which are so necessary for the synthesis of hormone-D.

The highest concentration of UV-B rays is from 11:00 to 14:00. But be careful and careful. At the same time, the risk of getting sunburn, since UV-B rays still have an erythemal effect.

So everything in moderation! As a rule, at noon it is enough to stay in the open sun for only 20-25 minutes to receive suberythemal doses of radiation. For children this time is even shorter. ATTENTION! You don’t need to stay in the sun for all 4 hours during the day, but only 20-25 minutes from 11 a.m. to 2 p.m. I ask you to carefully read the text and be sure to ask again in the comments if something has raised a question in your mind.

Cloudiness and air pollution

Another obstacle to vitamin synthesis in the skin is smog and air pollution, as well as cloudiness and fog. I have come across such a common opinion that it lights up well even with clouds. So it turns out that synthesis is reduced by more than 2 times.

And if you are still wearing sunscreen or clothes, then you should not count on a sufficient concentration of the vitamin in the body. And don't forget that UV-B doesn't penetrate glass.

Skin tone and vitamin D

Do you want me to surprise you now? The more you sunbathe, the less vitamin D you synthesize in your skin. In other words, the darker the skin, the less able it is to produce hormone-D. This, by the way, is a big problem among representatives of the Negroid race. They very often have a deficiency of this substance, although they may live in very sunny countries.

If you're dark-skinned, you'll have a harder time getting the vitamin D you need, even if you spend days baking on the beach. This will only make your skin darker, and vitamin synthesis, on the contrary, will slow down. This applies to both adults and children.

Movement enhances vitamin D absorption

Not only is vitamin D reproduced in the skin, it also needs to be actively transferred into the bloodstream, and this happens with intense physical activity. It turns out that physical inactivity leads not only to obesity, but also to a decrease in the absorption of the vitamin that was so difficult to form in your skin. By the way, it is likely that it is vitamin deficiency due to physical inactivity that leads to obesity.

But about the issue of relationship excess weight and vitamin D deficiency I will write a little later.

Like these ones Interesting Facts. If this was not enough for you, then I will give you this study as an example. It was carried out among newborns in Hawaii, where there is more than enough sun. We studied 100 cord blood samples from healthy full-term babies and their mothers.

As a result, 25(OH)D levels were significantly higher in summer. But 28% of samples showed a pronounced deficiency of vitamin D, i.e. the level was below 20 ng/ml, and 50% of samples revealed deficiency, namely 20-30 ng/ml. A pattern was also revealed that the deficit was greater in black participants.

And now, in view of new information, we must switch to the so-called “sun-catching” behavior, as well as the “fish-catching” and “vitamin-D-catching” diet.

That's all for me. In just a couple of days, an article will be published on diagnosing vitamin D deficiency and deciphering it. And now I have news for you.

I'm taking part in the competition! We need your support!

I decided to participate in the “Diabrand 2017” competition, or rather, our online store is a participant, since they did not have the “Diavrach 2017” or “Diablog 2017” nominations, otherwise I would have been better nominated for these categories.

Therefore, I ask my readers and friends to support my project and vote for the online store “Sugar is normal.” You can only vote from one IP and the voter must log in through one of social networks. Voting will last until September 30. And another very important condition is that you need to vote in other categories, otherwise your vote will not be counted.

To support and vote for us, follow this link or click on the picture. I rarely ask my readers for anything and only when absolutely necessary. And today that day has come. Your voice is important to me!

Now that's all for sure. See you again!

With warmth and care, endocrinologist Lebedeva Dilyara Ilgizovna