What vitamin is produced in the human body on its own. What vitamin does the sun provide? Vitamin produced in the sun Where are vitamins produced in the body

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It is not enough for a person to simply know which vitamin is produced in the body due to sunlight, its lack must be regularly replenished by eating eggs, fish oil, parsley, butter, mushrooms.

The human body is a comprehensively thought-out structure in which all processes are provided for and will occur without failures, if the necessary conditions are observed to ensure its vital activity. There are several types of vitamins that are produced independently, but in small quantities.

The intestinal microflora produces: choline, pantothene, thiamine, pyridoxine. Their quantity is not enough to fully ensure a healthy existence, so the main source remains their intake with food.

Thus, disputes about which vitamin A, B, or D are produced in the human body are groundless. Each group has its own role, its own sources of replenishment. It is not produced in any form only, which is responsible for many functions. Despite the body's ability to produce other groups naturally, nutrient supplementation with vitamins B and D is essential.

Despite the perfection of the structure of the human body, it turns out that many useful nutrients are not synthesized in it. Scientists suggest that this happened as a result of evolution. In the process of improving Homo sapiens, nature abolished the natural production of almost all vitamins in order to avoid unnecessary energy costs.

For a person who cares about his health, this fact is not so important. It is enough to know which vitamin is produced in the body in the human body. Another thing is important: despite the fact that the body synthesizes some vitamins, their content is not enough, and the balance must be replenished regularly. As for the vitamins of groups A, E, C, which are not produced at all, but play an important role in the course of vital processes, their replenishment is mandatory daily in accordance with the daily norm.

As you already understood, most of the vitamins enter our body with food. Therefore, it is very important to eat a balanced diet. And how to make a full-fledged menu will tell you a video course "Healthy eating: how to turn food into a source of longevity?". I recommend downloading it.

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The D vitamins (calciferols) include steroid compounds with antirachitic activity. The most important representatives of this group are cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2).

Calciferols are sensitive to the action of light and atmospheric oxygen, especially when heated. Calciferols are formed as a result of photoisomerization of the corresponding provitamins (7-dehydrocholesterol) under the action of solar or artificial ultraviolet radiation with a wavelength of 280-320 nm on the skin.

In addition, calciferols enter the body with food. Vitamin D is found mainly in animal products. They are rich in fish liver oil. It is found in very small amounts in plant foods.

Units of measurement of calciferols

Vitamin D activity is measured in international units (IU).

1 ME corresponds to 0.025 μg of ergo- or cholecalciferol.

1 microgram of vitamin = 40 IU.

Sources

Traditional food sources of vitamin D are cod liver, fish, fish oil, liver, egg, butter.

Physiological significance

The main functions of vitamin D in the body are associated with the maintenance of calcium and phosphorus homeostasis, the implementation of bone tissue mineralization processes.

The main processes in which vitamin D plays an important role:

Absorption of calcium and phosphorus in the intestine
- mobilization of calcium from the bones of the skeleton,
- reabsorption of calcium in the renal tubules.

Calciferols are absorbed in the small intestine, enter the liver, where they are converted into 25-hydroxycholecalciferol (25OND3) and 25-hydroxyergocalciferol (25OND2), which are supplied and determined by laboratory methods in the blood.

Calciferols are able to deposit (accumulate) in adipose tissue. Excreted from the body mainly with feces.

Increased need for vitamin D in people who lack ultraviolet radiation:

Living in high latitudes
- residents of regions with high air pollution,
- working on the night shift or just leading a nocturnal lifestyle,
- bedridden patients who are not in the open air.
In people with dark skin (blacks, tanned people), the synthesis of vitamin D in the skin may decrease. The same can be said about the elderly (they have a reduced ability to convert provitamins to vitamin D).
In pregnant and lactating women, the need for vitamin D increases.

daily requirement

Table. Norms of physiological need for vitamin D depending on age in Russia [MR 2.3.1.2432-08]

The upper permissible level of vitamin D intake for adults is 15 mcg per day (“Uniform sanitary-epidemiological and hygienic requirements for goods subject to sanitary-epidemiological supervision (control)” of the EurAsEC Customs Union) and 50 mcg per day according to the “Norms of physiological energy needs and nutrients for various groups. population of the Russian Federation. Guidelines MP 2.3.1.2432-08.

Symptoms of hypovitaminosis

A typical manifestation of vitamin D deficiency is rickets. Initially, non-specific manifestations of deficiency are observed: increased irritability, general weakness, sweating, for young children - belated teething, a tendency to bronchitis, slowing down the ossification of fontanelles.

In temperate and northern climates, the main cause of rickets is the lack of solar exposure of the child. Another cause of rickets is a lack of vitamin D in the diet. Vitamin deficiency leads to bone softness and characteristic deformities.

In adolescents and adults, the clinical manifestations of deficiency are manifested by pulling pains in the lower extremities, lethargy, and fatigue. There are changes in the diaphysis of bones, osteomalacia, osteoporosis develops. To assess the availability of vitamin D, the concentration of calcium, phosphorus and 25OND in the blood serum is examined.

Signs of vitamin D deficiency are:

In children
• increased irritability
• restlessness
• general weakness
• sweating
• delayed teething and ossification of fontanelles
• rickets
• spasmophilia
• susceptibility to respiratory diseases.

In adults
• lethargy, fatigue
• osteoporosis, crumbling teeth
• pelvic pain, duck gait, lameness
• muscle pain.

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Toxicity

Vitamin D in doses exceeding the physiological requirement by 200-1000 times is highly toxic, causing a state of hypervitaminosis with hypercalcemia and calcification of the tissues of internal organs (kidneys, aorta, heart), which leads to disruption of their functions.

Large doses disrupt the activity of the central and autonomic nervous systems, the cardiovascular system.

Intoxication when taking from 1 to several million IU of vitamin D occurs with general weakness, headache, joint, bone and muscle pain, numbness of the arms and legs, constipation, fever, arterial hypertension, conjunctivitis, hemorrhages on the skin; convulsions are possible.

* dietary supplement. NOT A DRUG

We acquire it through sunlight or through food. The ultraviolet rays act on the oils of the skin, promoting the formation of this vitamin, which is then absorbed into the body. Vitamin D is formed in the skin under the action of sunlight from provitamins. Provitamins, in turn, are partly supplied in the body in finished form from plants (ergosterol, stigmasterol and sitosterol), and partly formed in the tissues of their cholesterol (7-dehydrocholesterol (vitamin D provitamin 3).

When taken orally, vitamin D is absorbed from fat through the walls of the stomach.

It is measured in International Units (IU). The daily dose for adults is 400 IU or 5-10 micrograms. After getting a tan, the production of vitamin D through the skin stops.

Benefit: Properly utilizes calcium and phosphorus, necessary for strengthening bones and teeth. When taken together with vitamins A and C, it helps in the prevention of colds. Helps in the treatment of conjunctivitis.

Diseases caused by vitamin D deficiency: rickets, severe tooth decay, osteomalacia*, senile osteoporosis.

Vitamin D belongs to the group of fat-soluble vitamins with anti-rachitic effects (D 1 , D 2 , D 3 , D 4 , D 5)

The D vitamins include:

vitamin D 2 - ergocalciferol; isolated from yeast, its provitamin is ergosterol; vitamin D 3 - cholecalciferol; isolated from animal tissues, its provitamin - 7-dehydrocholesterol; vitamin D 4 - 22, 23-dihydro-ergocalciferol; vitamin D 5 - 24-ethylcholecalciferol (sitocalciferol); isolated from wheat oils; vitamin D 6 - 22-dihydroethylcalciferol (stigma-calciferol).

Today, vitamin D is called two vitamins - D 2 and D 3 - ergocalciferol and cholecalciferol - these are colorless and odorless crystals, resistant to high temperatures. These vitamins are fat soluble, i.e. soluble in fats and organic compounds and insoluble in water.

They regulate the exchange of calcium and phosphorus: they participate in the process of calcium absorption in the intestine, interact with parathyroid hormone, are responsible for bone calcification. In childhood, with vitamin D deficiency, due to a decrease in the content of calcium and phosphorus salts in the bones, the process of bone formation (growth and ossification) is disturbed, rickets develops . In adults, bone decalcification (osteomalacia) occurs.

The German chemist A. Windaus, who studied sterols for more than 30 years, in 1928 discovered ergosterol - provitamin D, which turns into ergocalciferol under the influence of ultraviolet rays. It was found that under the influence of ultraviolet rays a certain amount of vitamin D can be formed in the skin, and irradiation can be either solar, and with the help of a quartz lamp. . It has been calculated that a 10-minute irradiation of animals has the same effect on the body as the introduction of 21% fish oil into the diet. In irradiated foods, vitamin D is formed from special fat-like substances (sterols). Recently, ultraviolet irradiation of animals, especially young animals, as well as feed has been widely used in animal husbandry.

Main sources: fish oil, caviar, liver and meat, egg yolk, animal fats and oils, sardines, herring, salmon, tuna, milk. hay flour, Vitamin D is also found in large quantities in egg yolk, yeast, good hay, vegetable oil, grass flour and other products. Plants do not usually contain the vitamin, but they do contain the provitamin ergosterol, which is converted to vitamin D in animals.

daily requirement 2.5 mcg, for children and pregnant women - 10 mcg. Disorders of the intestines and liver, gallbladder dysfunction negatively affect the absorption of vitamin D.

In pregnant and lactating animals, the need for vitamin D increases, because. an additional amount is needed to prevent rickets in children.

Women who exhaust themselves with unbalanced diets, as well as women who give birth to many children, can suffer from osteomalacia, since the growing fetus and the child who receives breast milk consume vitamin D and calcium from the mother's body. However, in the vast majority of cases, osteomalacia is not a consequence of avitaminosis D (perhaps, with the exception of the starving population), but develops due to metabolic disorders, in particular, in renal failure. Osteomalacia can also develop in patients with epilepsy, which is associated with an increase in their activity of enzymes involved in the metabolism of vitamin D.

To treat these diseases, many preparations containing vitamin D have been developed. In osteomalacia and impaired calcium absorption from the intestine, large doses of this vitamin are needed, many times higher than preventive ones. In addition to ergocalciferol and cholecalciferol, structural analogues of vitamin D, dihydrotachysterol and alfacalcidol, are used as drugs, which do not require the participation of the kidneys in their activation. They are converted to the biologically active calcitriol in a single step in the liver and are therefore particularly suitable for patients suffering from renal insufficiency.

Vitamin D preparations are widely used for the prevention and treatment osteoporosis, in which thinning and resorption of the structural elements of the bone occurs, and other diseases associated with impaired calcium metabolism, as well as in some diseases of the thyroid gland.

Vitamin E is a natural antioxidant that protects body cells from free radicals. Free radicals are normally formed during metabolism and, if not inactivated, can interact with cell membrane lipids, destroying them and causing damage to cells. Therefore, the role of vitamin E, which absorbs free radicals, is so great in the life of the body.

Skeptics often say that vitamin E can never find a disease that it could treat. And this is partly true, since this vitamin is involved in a variety of processes that occur in our body. It improves blood circulation, is necessary for the flow of regenerative processes in tissues, helps to reduce blood pressure, plays a role in preventing the development of cataracts, is important for the normal functioning of the nervous system, maintains healthy hair and skin, slows down the aging process, promotes absorption and protects other fat-soluble substances from destruction. vitamins. And this list can be continued.

As a rule, the amount of vitamin E that enters our body with food is enough to prevent its deficiency, however, excessive consumption of processed foods in the form of fast food and culinary intermediates can lead to it. Therefore, for the purpose of prevention, vitamin E preparations or multivitamin preparations containing a sufficient amount of vitamin E are prescribed.

And in the dark and cold winter months, when there is so little sun and all sorts of colds and disease viruses are waiting on every corner, and in the hot and sunny summer, when it is so easy to burn in the scorching sun, the most important factor for maintaining immunity is a high level of vitamin D in the body, which depends on the amount of ultraviolet radiation received.

Numerous studies have been carried out on this issue, which often contradict data that was previously considered an indisputable fact and resulting from recommendations, often diametrically opposed to those previously cited. You've probably seen some vague guidelines, such as the recommendation to be in the sun for "a few minutes every day."

But these recommendations are too general to be helpful. The amount of sunlight it takes to meet your vitamin D requirement varies greatly depending on your location, skin type, season, time of day, and even atmospheric conditions.

Myths about sunbathing

1. Best 12am and after 3pm.
2. To maintain the required level of vitamin D in the body, it is enough to expose the hands and face to the sun 2-3 times a week for 5-15 minutes during the summer months.
3. Going to the sun, always use sunscreen.

one. . Sunbathing is best between 12am and after 3pm The optimal sun exposure time for vitamin D production is around noon, approximately between 11am and 3pm.
The fact is that ultraviolet radiation includes a wavelength of a different range, which is divided into three groups:
UV-A (UVA) (315-400 nm) , UV-B (UVB) (280-315 nm) UV-C (UFS) (100-280 nm) UV-A and UV-B can pass through the ozone layer, in order to reach our skin, but they are very different when it comes to their individual characteristics.

UVB rays:
-. responsible for triggering the production of vitamin D in the skin
- Causes sunburn.
- they cannot penetrate glass or clothing.
- It is active only at certain times of the day and year.

UVA rays
- do not cause the production of vitamin D in the skin.
- do 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 throughout the year throughout the day between 11 am and 3 pm with relatively short sun exposure to get vitamin D because UVB rays are most intense at this time.
But we have to be very careful with the amount of time we spend in the sun.

Remember that this is enough if the skin has turned a little pink. For some people it will only take a few minutes, for some it may take an hour or more.
After that, the chances of sunburn increase, and this is definitely what we want to avoid. The fact is that the body can only produce a limited amount of vitamin D per day. After it reaches its limit, further exposure to the sun will only harm and damage the skin. When the sun sets below the horizon, much more UVB is filtered out than dangerous UVA.

So it's entirely possible that being in the sun at 9am or 5pm will cause your vitamin D levels to drop, as there's evidence that UVA destroys it.

So if you want to get out in the sun to optimize your vitamin D production and minimize your risk of malignant melanoma, mid-afternoon is the best and safest time.

2. To maintain the required level of vitamin D in the body, it is enough to expose sunny hands and face 2-3 times a week for 5-15 minutes during the summer months.

It is believed that for most people it is enough to have 15 -minute exposure to UV radiation to form vitamin D in the skin, according to doctors' recommendations, how much vitamin D should be produced daily to maintain health.

However, once you get a tan, you will need to spend a lot more time in the sun. If you have dark skin, reaching the balance point can take two to six times longer (up to an hour or two) depending on the pigmentation.

White-skinned people quite far from the equator (for example, in the UK or the United States in the north, central Russia) need at least three 20-minute sessions per week in bright midday sunlight and with a minimum of clothing.

Dark-skinned people, of course, need to be much larger and often in the sun to get the same effect. This information is just beginning to filter through the media, so it's important to emphasize this point.

3. Going to the sun, always use sunscreen. Keep in mind that using sunscreen does a lot to negate your efforts to absorb enough vitamin D.
It is advisable to make sure you do not have a vitamin D deficiency before resorting to any kind of sunscreen.
But if you really need some form of protection when you're out in the sun for an extended period of time, it's best to use light clothing to cover exposed areas, or look for safer, natural sunscreen products that don't contain oil.

It's also important to remember that if you're using the sun or a safe tanning bed to get your vitamin D, be aware that it takes about 48 hours for vitamin D to fully pass from your skin into your bloodstream, and you can easily wash it off with soap and water.

Thus, it makes sense to limit your minimum hygiene routine for at least 48 hours so that all of your vitamin D has been absorbed. As strange as it sounds, flushing can degrade one of the main ways to stay healthy.

4. Using a tanning bed can help collect missing vitamin D during the winter.
In the winter, many people use the bed to prepare their skin for the summer sun, to maintain their vitamin D levels, to prevent winter depression, and just for beauty.

If someone is in a commercial place, remember that it is advisable to ask the owners about what lamps they use. There you have tanning beds that use both UVA and UVB radiation in varying proportions, and in some only UVA is used. As noted above, to produce vitamin D, there needs to be UVB radiation. In natural sunlight, the UVA and UVB ratio is about 2.5-5.0% of UVB, respectively, while in a tanning bed with 5% UVB and 95% UVA, it is about the same as if you were in bright sunlight. sunlight in the middle of the day and this is enough to get enough 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 steps must be delivered to. on the one hand, due to excessive caution, so as not to deprive himself of what he takes for the body, in order to maintain good health, and on the other hand, not to harm himself, ignoring the danger.
The accurate data that OpenWeatherMap delivers to the IT market using the most modern technologies (for example, Big Data) can be, and in many areas already, the basis for products that can help people get accurate forecasts and recommendations for maintaining and protecting their health. .