We get vitamin D from the sun. Vitamin D (calciferol, antirachitic)

A laudatory ode to the "vitamin of the sun"
Vitamin D was discovered in the 20-30s of the last century, and the first studies have already shown that such diseases as rickets, bone curvature and spinal deformity are associated with a lack of this vitamin in a child's body. 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 is calciferol or vitamin D.

Perhaps someone will doubt whether we, adults, should attach such importance to the “children's” vitamin, because the time for the formation of the skeletal system has long passed, rickets no longer threatens us. It turns out that vitamin D is not so simple, and its physiological role is not only in 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 violations in work and in the battle against infections, helps the smooth functioning of the heart, and regulates the activity of the nervous system. Vitamin D is necessary for normal blood clotting, prevents the development of atherosclerosis, is important for the functioning of the thyroid gland and normal blood clotting, and helps to get rid of many eye diseases. Women who have sufficient levels of vitamin D in the blood are less likely to have benign and malignant breast tumors and ovarian cancer.

So, vitamin D is necessary for everyone and always - both in childhood, and in blooming youth, and at the age of elegance, and at sunset. As soon as we stop caring about supplying our body with this vitamin, problems pile up, ranging from aching bones, back pain, and ending with fractures, depression, memory impairment, problems with blood pressure, and you never know what else can happen if you neglect sunshine vitamin.

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

It is also important to note that vitamin D is fat soluble, it is not washed out of the body with fluid, but rather slowly excreted in the bile, so it is quite possible to store some inactive vitamin D in the liver for several months.

How vitamin D is formed in the skin, or some of the nuances of sunbathing ...
is the main source of vitamin D in the body. Under the sun's rays, on the surface of the skin, covered with a thin layer of cholesterol-like substance ergosterol and sweat, vitamin D is formed, which is then absorbed by the skin, penetrates into the bloodstream and ultimately enters the liver, where then, during metabolism, its transformation into active forms begins. Moreover, part of the inactive vitamin D is deposited in reserve in special liver cells - reticulocytes, which ensures that the body maintains the required level of its active forms for several months. In the liver, the process of converting the so far passive calciferol into the active hormone calcitriol begins and ends in the kidneys, and it is from here that this hormone sets out 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 through the rest of the year.

Sunbathing to replenish vitamin D(and not for chocolate tanning) some features should be considered:

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

Also, do not rush to take water procedures immediately after sunbathing, give the vitamin time to be absorbed into the skin;

They protect us from ultraviolet radiation and at the same time block the ability of the skin to produce vitamin D. Sunbathing without sunscreen within 15-20 minutes in the morning and in the late afternoon, several times a week, according to experts, it is able to provide 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 you tan, the lower the skin's ability to produce vitamin D.

It should also be taken into account that the skin is able to efficiently produce vitamin D when exposed to ultraviolet rays in a clean atmosphere, so walking through the city streets, over which a haze of dust and exhaust gases hangs, is unlikely to promote health and accumulation of the vitamin.

Give the sun a chance!
And what happens? If we, following the recommendations of dermatologists-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 vitamin D that we need so much. our skin is already covered with a chocolate tan and it is not afraid of burns, we no longer use a protective cream so strictly - and our own tan is already getting in the way of vitamin D synthesis.

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

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

Alternative ways
The second way that 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 of marine fish (herring, mackerel, tuna, mackerel). There are also vegetable sources of vitamin D - parsley, nettle, mushrooms, alfalfa, horsetail - however, its content in them is very small.

The daily requirement for a vitamin that enters the body with food is approximately 200 international units / ME /, this is if you are daily outdoors under the influence of sunlight for 30 minutes. If sunbathing is not for you, then the norm increases to 1000 IU.

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

As you can see, even with a complete diet, the body's need for a vitamin is difficult to fully meet through food. The combination of sunlight and the right choice of menu is the most reliable way to solve the problem.

You can also diversify your diet with foods additionally enriched with vitamin D, these are milk, yoghurts, breakfast cereals, cookies, 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, to 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 your vitamin D reserves with the help of vitamin preparations. Before deciding on the use of vitamin preparations, consult your doctor. You should not take vitamin D in larger quantities than you need, its excess is just as dangerous as its deficiency.

In the meantime, summer reigns, the sun is shining, it’s too early to think about medicines, spend more time outdoors, catch the “sunshine vitamin” with all bare parts of the body, but do not forget about safety rules.

D (the second name is calciferol) is both a fat-soluble vitamin and a hormone. Traditionally, it is called "", as it is easiest to get it by sunbathing in the summer under the sun. Let us consider in more detail its varieties, features, benefits for the body and recommendations for use.

Vitamin Forms

There are two active forms that are currently commonly referred to as vitamin D:

• D2 - (synthetic) plant origin, appears as a result of exposure to UV rays on a yeast fungus. It is included in dietary supplements and enriched with food.
• D3 - (natural), it can be found in animal products.

In addition to these two main forms, the D vitamins include the following: provitamin D3 (vit. D4), D5 - sitocalciferol, D6 - stigma-calciferol. The difference between them lies in the source, synthesis in the body and use. Speaking of calciferol, most often suggest D2 and D3.

It enters the body in two ways: from food and as a result of synthesis from provitamins under the influence of sunlight. It is quite well preserved during cooking, as well as.

What is vitamin D for?

D has an extensive beneficial effect on the human body, affects the health of various systems.

• Bone system. The main function of D is the absorption of calcium and magnesium for the subsequent formation of healthy teeth and bones. It also promotes better absorption of calcium in the intestines and kidneys, regulates the amount of calcium and phosphorus in the blood. This is its main hormonal function.
• Immunity. D affects the bone marrow, which is involved in the synthesis of monocytes - immune cells, thereby increasing immunity.
• Cell growth. D is directly involved in the growth, development and maintenance of healthy cells. The benefits of vitamin D in this matter are invaluable: the hormone provides high-quality protection of the body from malignant diseases, slows down the development of oncology in the skin, breast and colon. Effectively treats leukemia, ovarian, breast, prostate, brain cancer and is a good prevention of these ailments.
• Nervous system. Helps to maintain normal levels of calcium in the blood, ensures the normal functioning of muscles and nerves, helps to restore the protective sheaths surrounding the nerve.
• Hormones. The vitamin coordinates the production of insulin in the pancreas, thereby affecting blood glucose levels.

Where and how to get vitamin D?

If a person receives a sufficient amount of D in the summer, sunbathing in the sun, then he is saturated with the necessary supply for the whole year. Vitamin is actively synthesized from provitamins, but the quantity and quality of this process depends on several factors:

• The length of the light wave. Of great benefit are the waves of the middle spectrum, which are active in the morning and at sunset.
• The age of the person. The older the skin, the worse it synthesizes D.
• Primary pigmentation. The darker the skin, the less the vitamin is produced by exposure to the sun.
• Atmospheric pollution. Dust, industrial waste and emissions prevent ultraviolet rays from fully reaching the earth's surface, so people living in industrialized cities with a polluted atmosphere are deficient in D.

Also, an increased need for the vitamin is experienced by people living in the North, in high latitudes, leading a nocturnal lifestyle and bedridden patients who rarely go outdoors. Pregnant and lactating women are at risk.

food sources

Calciferol can be additionally obtained from fish oil and fish (mackerel, herring, sardines in oil, tuna, salmon), liver, and dairy products. Fish and fish oil are the best source of vitamin D, the worst on this list are dairy products: they are low in the vitamin and contain phosphorus, which interferes with the normal absorption of D.

The average daily intake of D for adults is 5 mcg (300-600 IU), should not exceed 15 mcg. For children, the daily requirement is 400-500 IU. For accurate calculations, especially if the vitamin is prescribed as a therapeutic dietary supplement, it is recommended to look at a special table. In it, you can clarify the daily dosage depending on gender and age for specific years.

How does vitamin D deficiency manifest itself?

This problem appears infrequently, mainly in those people who are rarely in the sun. Elderly people who rarely go out for a walk, as well as bedridden patients, suffer from the lack. D deficiency can be identified by the following symptoms: poor health, increased fatigue, the appearance of fractures and their long healing, bone demineralization.

If a child does not get enough D, he develops rickets. Such vitamin deficiency reduces the process of calcium absorption, secondary hyperparathyroidism develops, which leaches calcium from the bones and removes phosphates in the urine. You can determine the development of rickets in children by the following signs:

1. softening of the cranial bones, thickening of the nape, the formation of layers in the crown and frontal areas;
2. Deformation of the facial skull;
3. Change in the shape of the chest;
4. Curvature of the lower extremities, deformity of the pelvis;
5. Slowing down teething and fontanel closure;
6. increased sweating, irritability, sleep problems.

Pregnant and lactating women should especially monitor their diet and lifestyle, since both the mother and her child need a good dose of vitamin. All the necessary recommendations on an individual basis will be given by a gynecologist. The general recommendation is to take the vitamin in an amount of 1500 IU per day during pregnancy. Pregnant women can get calciferol from fish oil (2 tablespoons - natural, 1.5 tablespoons - medical), take 1-2 drops of ergocalciferol.

How does excess vitamin D manifest itself?

Despite the useful value, D and others for the human body, they can also cause harm in case of an overdose. Excess can provoke an increase in calcium in the blood, from bone tissue it passes into other tissues and organs, is deposited in the heart, arteries, kidneys, liver and lungs. Due to metabolic disorders, the skeleton becomes fragile.

Excess often occurs with arbitrary increase in doses (for example, when mothers increase the dosage for their children without consulting a pediatrician). You can determine an overdose in a child by the following symptoms: poor growth and weight gain, poor development, decreased appetite, increased irritability. Of particular danger is an overdose of calciferol along with prolonged exposure to the sun, as well as large doses of fish oil.

An overdose at the initial stage in an adult is manifested in the following symptoms: loss of appetite, extreme thirst, nausea, weight loss, polyuria (increased amount of urine), constipation, muscle problems, high blood pressure.

Long-term overdose leads to an increased content of calcium in the body, hypercalcemia occurs. The following signs of hypercalcemia are distinguished: muscle spasms, severe convulsions, calcium deposition, irritability.

To avoid such negative consequences, it is necessary to carefully observe the dosage of the vitamin prescribed by the doctor.

Now you know what vitamin D is good for, what it is responsible for, where you can get it from, why it is important to monitor its correct dosage and how to use it. If you are a healthy person who often walks on the street and actively relaxes in the summer, you should not worry about its lack, unlike. Particular attention should be paid to this vitamin for pregnant and lactating women, pensioners and people who, for one reason or another, rarely go outside during the daytime.

Vitamin D has been among the vital substances discovered and studied by science for about a hundred years. Everyone has probably heard about the benefits of the solar vitamin, but what exactly is it useful for? This article will tell you about what vitamin D is like, where it is contained, what is dangerous about its deficiency and excess.

Often, all D vitamins are collectively referred to as calciferol, despite the fact that this is the name of a specific vitamin - D3. In medical practice, vitamin D is understood to mean the D2 and D3 forms; they are considered the most active and therefore the most effective in providing the necessary action. The functions of all these vitamins are similar, so we can say that they differ mainly in activity and method of obtaining. In published articles, they are most often not separated, even doctors, when talking about vitamin D, mean all of its forms. If we are talking about a specific vitamin, it is mentioned separately.

According to modern science, vitamin D comes in six forms:

• D1- a form that has in its composition two steroid derivatives, ergocalciferol and lumisterol. It was first found over a hundred years ago in cod liver. In its pure form, the vitamin is not found and can only be obtained through chemical synthesis. D1 contributes to the normal growth of bone tissue, controls the level of macronutrients in the body. With sufficient intake, it can be stored in muscle and fat tissues and consumed as needed.
• D2, or ergocalciferol, is formed by exposing ergosterol to ultraviolet rays. In nature, it is synthesized by fungi. D2 can be called both a vitamin and a hormone at the same time - it regulates the level of calcium and phosphorus and at the same time affects the functioning of internal organs using its own receptors. If the body needs calcium or phosphorus, it begins to actively synthesize this vitamin or consume its reserves.
• D3, or, in other words, cholecalciferol is the most important vitamin of its group. It is involved in a huge number of processes at the organismal level, affects most systems - nervous, circulatory, immune.
• D4- dihydroergocalciferol - is responsible, like other vitamins of group D, for maintaining metabolism and controlling macronutrients. But, unlike the others, it has a special function - it is responsible for the production of a special hormone by the thyroid gland, which removes calcium from the body's bone reserves into the blood.
• D5, or sitocalciferol, in its structure and properties is very similar to vitamin D3, but much less toxic. Thanks to this, the vitamin is successfully used in medicine - for example, in anti-inflammatory therapy and in the treatment of diabetes.
• D6, otherwise stigmacalciferol, is considered a vitamin with low activity. Responsible for the prevention of osteoporosis and rickets, ensures the normal development of the skeletal system.

Indications for use

Vitamins of group D are prescribed for therapeutic and prophylactic purposes. In the first case, the vitamin is taken in combination with the main therapy, most often for diseases with pathologies of the skeletal system and a lack of calcium in the blood. The difference between therapeutic and prophylactic methods is only in the dosage: in the treatment, the drugs are taken in a daily amount of 100-250 mcg, in the prevention - 10-15 mcg.

• Treatment and prevention of rickets
• Fractures and their poor healing
• Osteoporosis
• Hypothyroidism
• Liver disease
• Increased bone fragility
• Chronic gastritis, pancreatitis
• Low levels of vitamin D in the body
• Dental disorders
• Tuberculosis
• Diathesis

Contraindications

Despite all the benefits of vitamin D, there are a number of diseases in which its use is contraindicated:

• Hypercalcemia (excess calcium in the blood)
• Ulcers of the stomach and duodenum
• Active form of pulmonary tuberculosis
• Vitamin D hypervitaminosis
• Acute renal failure
• Heart defects
• Ischemic disease
• Chronic kidney disease

Vitamin D should be taken with caution if:

• atherosclerosis
• Heart and kidney failure
• During pregnancy and lactation

Dosage

Even for a healthy person, the dosage of vitamin D is not the same. It all depends on age, weight, and other factors. Normally, the dosage of a vitamin is considered to be approximately as follows:

• For infants up to 1 year old - 7-10 micrograms (280-400 IU)
• For children from 1 to 5 years old - 10-12 mcg (400-480 IU)
• For children from 5 to 13 years old - 2-3 mcg (80-120 IU)
• For men and women over 13 years old - 2-5 mcg (80-200 IU)
• For older people after 60 - 12-15 mcg (480-600 IU)
• For lactating women - 10 mcg (400 IU)

To indicate the dosage of vitamin D, micrograms (mcg) and international units (IU) are used. These units of measurement are interchangeable. One international unit is equal to 0.025 mcg, and one microgram is equal to 40 IU.

The dosages indicated in the list are optimal in order to safely replenish the reserves of the vitamin. The maximum allowable daily dose for an adult is considered to be 15 mcg. Its excess can provoke hypervitaminosis and, as a result, the manifestation of unpleasant symptoms.

What is contained?

Vitamin D is often referred to as the sunshine vitamin, and for good reason. Almost all of its forms, except for D2, are synthesized in the epidermis of the skin under the action of ultraviolet radiation. Provitamin D3 is converted to cholecalciferol (directly D3) due to thermal isomerization, after which it enters the bloodstream and is transported by it to the liver.

In summer, the vitamin is enough for the body to function normally, but in winter its production is significantly reduced. A large amount of clothing and a short daylight hours do not allow it to be synthesized in normal quantities.

In addition to synthesis in the human body, vitamin D is found in food, and for the most part in animal products. So, there is a lot of it in any meat, fish, meat and fish liver, eggs. The high content of the vitamin was also noted in fermented milk products.

There is practically no vitamin D in plant foods. It is found in small amounts in corn oil, potatoes, and parsley.

Scarcity and surplus

deficit Vitamin D is noted in every tenth inhabitant of our planet. A person suffering from hypovitaminosis gets tired quickly, he develops weakness, muscle pain, problems with teeth, vision. If you do not pay attention to these symptoms in time, the patient may face more serious diseases - rickets, osteoporosis, arthritis, bone deformities.

Rickets mostly small children are affected. With a lack of vitamin D, they may experience hair loss, sweating, problems with teething. In severe cases, the bones of the chest can be deformed and softened, a hump appears. Therefore, it is important for pregnant women to ensure that the level of the vitamin remains normal, and infants are allowed to give it from the first months of life.

Osteoporosis - Another disease associated with hypovitaminosis. It is most common among middle-aged and older people and leads to the fact that any, even a slight bruise, leads to cracks or fractures of the bones. To date, it cannot be completely cured, only additional vitamin D and pain medications can be taken.

Often depression and migraine are included in this list of diseases, explaining their development by beriberi.

Overdose Although less common, it still exists. Vitamin D tends to accumulate in the body, and its overabundance can cause convulsions, impaired heartbeat and breathing, weakness, nausea, and high blood pressure. Sometimes atherosclerotic plaques are formed on the walls of blood vessels associated with excess calcium.

Hypervitaminosis can occur only in the case of taking large doses of preparations containing vitamin D. Long exposure to the sun does not threaten an overabundance - sunburn protects human skin from this.

Treatment consists of discontinuation of the vitamin and a plant-based diet. Sun exposure should also be avoided. In some cases, it is required to take drugs that remove calcium from the body, or even hospital observation.

Vitamin D deficiency or excess can be detected with a blood test. For greater reliability, it is recommended to stop taking vitamin complexes and preparations that may contain it for several days before donating blood.

Side effect

There are many side effects of vitamin D. They can appear in two situations - in case of misuse or due to individual intolerance. Among these effects are low blood pressure, weakness, irritability, nausea. If you systematically exceed the daily norm of the vitamin, calcifications can form in the organs.

Preparations containing vitamin D

Aquadetrim

The most famous and safe drug that is suitable not only for adults, but also for young children. One drop contains about 600 IU of the vitamin, which is an approximate daily allowance. The drug is prescribed for the prevention of rickets, it can be taken regardless of the time of eating. It is recommended to dilute in a spoonful of water.

Alpha D3-Teva

The drug is available in the form of capsules with an oily solution. Approved for use by children over 6 years of age and adults - young children cannot swallow the capsule whole. Contains a synthetic analogue of vitamin D, is prescribed for patients with endocrine system disorders. It is necessary to take one or two capsules after meals with clean water.

Vitamin D3

It is an oily solution and is taken similarly to Akvadetrim. It can be used in the form of injections, the injection is given intramuscularly in the thigh or buttocks.

Calcium D3-Nycomed Forte

Available in the form of tablets with a citrus or mint flavor. One tablet contains the daily value of vitamin D3 and calcium. Taken after or with meals, intended for children over six years of age and adults.

Vigantol

The drug is produced in the form of an oil solution. Suitable for children from birth and adults, prescribed for the prevention of rickets, the treatment of osteoporosis.

Vitamin D became known for its activity against rickets, a disease described in the mid-17th century. In the first quarter of the 20th century, experts were able to prove that ultraviolet irradiation of patients gave positive results in the treatment of the disease. A few years later, this was associated with the action of vitamin D - the substance was obtained in free form and was able to prove its properties.

The compound is represented by a group of similar substances (among which vitamin D2 - ergocalciferol and D3 - cholecalciferol, D 4 - dehydrocholesterol, D 4 - dehydrocholesterol, D 5 - sitocalciferol, D 6 - stigmacalciferol) can be distinguished. In total, 6 modifications of the vitamin are known. Substances have biological activity.

Physico-chemical parameters of calciferol

The vitamin has a structure that is soluble in fatty media. It is presented in the form of a white powder of a crystalline structure with a melting point of about 120 degrees. Calciferol is highly soluble and miscible with almost all organic solvents - alcohols, vegetable oils and animal fats.

Foods high in vitamin D

Most substances can be found in fish of almost all varieties (sardines in oil, salmon, herring, tuna, mackerel). Also, a sufficient amount of the vitamin is found in dairy products, liver and egg yolks.

A certain amount of the vitamin can be found in algae, mushrooms (especially chanterelles) and fish oil. Less vitamin D can be found in cheeses, caviar and butter.

In the industrial production of vitamin for dietary supplements, yeast is used as a raw material to obtain the compound.

Vitamin preparations

Vitamin exists in 6 forms, which are completely similar in action to each other: the only difference is in the way they are synthesized and obtained. In preparations, the compound can be presented as a single dietary supplement, as well as a dual-action agent - for example, when combined with calcium. There are many modifications of products with vitamin D - ointments and creams (Psorkutan, Silkis, Daivonex), calcium mixtures (Natekal D3, Calcemin Advance, Calcium D3 Nycomed), oil solutions (Oxidevit, Vigantol, Etalfa), vitamin complexes (Complivit Calcium D3, Alphabet kid, Vitrum, Polivit, Multi-Tabs).

Vitamins should be taken in accordance with the daily dosages and instructions. It should also exclude the presence of hypersensitivity to the components of drugs and side effects. The prophylactic course of admission is a month, it is optimal in such cases to drink vitamin-mineral complexes.

The substance can act as a prophylactic against softening of bone tissue and rickets.

Main testimony The preparative use of vitamin D includes the following conditions:

• lack of substance in the body;
• osteoroposis;
• hay fever;
• chronic gastritis;
• arthritis;
• muscle tetany;
• lowering the calcium-phosphorus level in the blood;
• fractures and slow recovery of bone tissue;
• pancreatitis;
• inflammatory processes in the bone marrow;
• liquefaction of bone tissue;
• instability of the functioning of the thyroid gland;
• systemic lupus erythematosus;
• tuberculosis.

It is important to avoid overdosing and ensure that negative side effects do not appear when additionally taking the drug.

How much substance should be consumed per day

The average daily dosage for an adult is about 400 international units (equivalent to 5-10 mcg.). The maximum allowable value for daily intake is 15 mcg. Children need vitamin D more than adults, so it is acceptable for them to increase the dosage to 500 IU or more.

Some of the substance is synthesized by the body itself when exposed to the sun - human skin is able to form vitamin D under the influence of ultraviolet radiation. Those who are often in the sun usually do not need to take extra vitamin D. But people who rarely find themselves in direct sunlight are advised to make up for the lack of connection by taking specialized dietary supplements.

What are the benefits of viosterol

Vitamin D It has a number of useful properties that make it an indispensable substance for maintaining health and well-being. Connectivity features include:

1. regulation of calcium-phosphorus metabolism in body systems;
2. influence on the process of formation of the skeleton, bone tissue and teeth in childhood;
3. participation in the growth, formation and development of cellular structures;
4. control over the formation of insulin in the pancreas;
5. prevention of the development of leukemia, as well as cancerous tumors in the brain, ovaries, mammary glands, prostate,
6. influence on the hardening of bone growths and the healing of fractures;
7. stabilization of blood glucose levels;
8. restoration of the sheaths of nerve fibers;
9. increased absorption of calcium and magnesium ions.

Negative properties of a substance

Due to the fact that vitamin D does not dissolve in water, with an excess content in the body, it will not be possible to remove it without consequences and difficulties. With prolonged use of the substance in high dosages (about 25 thousand international units), the compound can have a toxic effect on various systems.

Among the main symptoms of poisoning are:

• inflammation of the eyeballs;
• itchy sensations on the skin;
• nausea and vomiting;
• increased calcium deposition on the walls of blood vessels, in the kidneys, liver tissues, lungs and gastric mucosa;
• diarrhea, indigestion;
• sudden urge to urinate.

Insufficient vitamin content in the body

Hypovitaminosis of ergocalciferol is very common. With insufficient intake of vitamin D or lack of sunlight, the following deviations may occur:

• dental disease, destruction of enamel and tissues;
• rickets;
• insomnia;
• lack of tone and energy;
• deformation of the bones due to their softening due to lack of calcium and vitamin D;
• thinning of bone tissue (especially for the elderly);
• weight loss;
• slow body growth;
• blurred vision;
• muscle weakness.

If the lack of a substance is severe, more serious abnormalities can develop - for example, Crohn's disease, in which complex intestinal inflammations occur. Lesions are localized throughout the mucosal area. In the absence of prompt and adequate treatment, some elements may be irreversible and lead to narrowing of the intestinal lumen, the formation of ulcers, abscesses. Often there are also cracks and local bleeding.

Ergosterol overdose

With excessive use of the vitamin, its toxic effect on the body can manifest itself. The main symptoms of an overdose in the body include:

1. nausea and vomiting;
2. loss of appetite;
3. increase in blood pressure;
4. deviations in renal activity;
5. disorders of the stool and stomach;
6. joint pain.

Avoid getting an increased amount of vitamin in the body. This can happen if a person takes specialized dietary supplements for a long time, allowing overdose. The duration of sun exposure also matters - those who are often exposed to sunlight usually do not need an additional intake of a synthetic vitamin.

In uncomplicated forms of overdose, taking vaseline oil can help.

How Vitamin D is Absorbed

Part of the vitamin is synthesized independently in the skin, and partly obtained by the body from food. With the self-production of the substance, the compound can be absorbed into the body directly through the epidermis, since the formation of calciferol occurs when natural skin oils are exposed to light.

When additionally taken in preparations, the compound is absorbed through the stomach. To make this process as efficient as possible, it is recommended to simultaneously provide a sufficient amount of retinol acetate, tocopherol, ascorbic acid, B vitamins, as well as calcium and phosphorus trace elements in the diet.

Medicinal interactions of vitamin D and other substances

Calciferol interacts well with retinol acetate and ascorbic acid - in this combination, a mixture of vitamins well prevents the development of colds. When used together with vitamins A, E, C, the compound contributes to their better absorption into the blood and maximum absorption. A similar effect is observed when used simultaneously with calcium and magnesium ions.

Retinol acetate in combination with vitamin D can prevent cholesterol and calcium deposits on the walls of blood vessels.

Vitamin D- a necessary substance for the proper functioning of many body systems. Part of the substance can be synthesized by the skin on its own during sunburn - the formation of the vitamin is facilitated by the irradiation of skin oils with light. The compound has a fat-soluble structure, so it is advisable to avoid overdoses - it will not work to remove excess substances through the kidneys. The lack of vitamin D group is also dangerous, since in this case the strength of the skeleton can suffer and many dangerous diseases can develop. With insufficient exposure to the sun, it is recommended to additionally take a vitamin as part of dietary supplements.

Greetings, friends! Summer is coming to its logical conclusion and I decided to extend it with my articles. Let's answer this question: "What do we know about vitamin D?" In the modern philistine view, this is a substance that children need so that there is no rickets - a severe violation of calcium-phosphorus metabolism.

Is it only this, undoubtedly important, role that the solar vitamin plays? Today, your understanding of this substance will change once and for all. Let's start!

Biochemistry of Vitamin D

And I want to start a little with the biochemistry of vitamin D: where it is synthesized, what stages of metabolism it goes through.

Our mothers and grandmothers drove us outside so that we would be more in the fresh air under the sun. And not in vain! After all, they knew that under the action of sunlight, namely the UV-B spectrum with a wavelength of 290-315 nm, a very valuable vitamin is synthesized in the skin, which protects against the pathology of the bone and muscle systems.

Indeed, cholecalciferol (Vitamin D3) is synthesized in the skin from a substrate called 7-dehydrocholesterol (read cholesterol). After that, this form of vitamin binds to a carrier protein and rushes into the bloodstream (see photo above). In addition, a small amount comes from food.

Further, in the liver, cholecalciferol is converted by hydroxylation into the active metabolite 25-hydroxyvitamin D3, which is designated as 25 (OH) D3 or simply CALCIDIOL. It is by this laboratory marker that we look at whether there is enough vitamin D in the body.

The next step with the blood flow, this form of the vitamin enters the kidneys, where it undergoes another hydroxylation reaction and as a result a metabolite is formed with the complex name 1,25-dioxycholecalciferol or 1,25 (OH) 2D3 or simply CALCITRIOL.

This is the most active and most unstable form of vitamin D. It is due to this metabolite that all its biological effects are realized. Calcidol binds to its carrier protein (VDBP) and is carried throughout the body to do good deeds.

Biological effects of solar vitamin

The effects of vitamin D are divided into:

• Genomic
• Extragenomic

Impact on genes

Almost every cell in our body has a special docking site for vitamin D on its surface - this is the VDR receptor. The receptor has two domains that bind to the vitamin and the cell's DNA.

Yes, it's not a typo. The uniqueness of vitamin D is that, through its receptor, it immediately acts on cellular DNA, giving a signal for the implementation (expression) of a particular gene.

Just think about this phrase: "Vitamin D regulates the DNA of every cell in the body." This is especially true for the tissues of the skin, large intestine and adrenal cortex.

There are special sections on DNA that react to the presence or absence of this important substance. They are called vitamin D-binding elements (VDRE).

When the active metabolite CALCITRIOL, which is 100 times more active than calcidiol, lands on its VDR receptor, this receptor immediately connects to the nuclear DNA, namely to individual DNA regions (VDRE) and the fun begins.

Processes that are programmed in a certain gene are launched, for example, the synthesis of a specific protein for some system, for example, the immune system. Vitamin D affects the levels of other hormones, growth and inflammation factors, numerous proteins, and, of course, calcium levels in the blood.

It has already been established and proven that vitamin D controls more than 200 genes, but it is also assumed that this number actually reaches 5000 genes. By the way, only 7-10% of the genes of the total number of genes controlled by Vit D are involved in the regulation of calcium in the blood.

So, if you thought that vitamin D is only responsible for the development of bones, then you are greatly mistaken; we were all greatly mistaken, since the spectrum of action of this substance is much wider and larger.

It is because of its mechanism that vitamin D is now considered not a vitamin at all, but a real hormone. Only hormones have the ability to influence how DNA works!

And recently it became known that this substance can have an epigenetic effect. The prefix "epi" means "above", that is, supragenetic influence. In other words, vitamin D can change the information recorded in our genes, that is, affect the genes by changing them.

This occurs due to processes with complex names - DNA methylation, acetylation of DNA-stabilizing histone proteins, and others. Maybe someday I'll try to talk more about it. not to miss.

Extragenomic effects

But vitamin-hormone D also has non-genomic mechanisms of action on the cell. As a rule, this is the control of the work of various enzymes in the cell matrix (adenylate cyclase, phospholipase, protein kinase, and others), the effect on mitochondria, and therefore active participation in the energy supply of cells.

What controls vitamin D

1. Calcium regulation, namely intestinal absorption and bone remodeling. With a deficiency, rickets, osteoporosis, osteomalacia develop.
2. Cell cycle regulation, i.e. so that the cell grows, develops and dies in time. With a deficiency, the risks of many types of malignant oncological diseases increase, especially cancer of the prostate, breast, colon and rectum, and leukemia.
3. Influence on the immune system, namely on the work of macrophages and the synthesis of antimicrobial peptides. Lack leads to frequent infectious diseases, up to tuberculosis, as well as autoimmune disorders (type 1 diabetes, autoimmune thyroiditis, multiple sclerosis, psoriasis, ulcerative colitis and Crohn's disease and others)
4. Participates in the synthesis of insulin. Vitamin D deficiency leads to impaired insulin secretion, glucose tolerance and diabetes mellitus.
5. Regulation of cardiovascular diseases. If the vitamin is not enough, then high-renin (renal) hypertension develops, increased thrombus formation, the risks of heart disease, myocardial infarction in particular, increase.
6. Controls the muscular system. Deficiency leads to various myopathies.
7. Affects the functioning of the brain. With a lack of vitamin during fetal development, the risk of behavioral disorders in adulthood is high, and in adults the risk of Parkinson's disease and mental degradation increases.
8. Participates in regeneration (wound healing, regulation of inflammation processes).

The listed list is a small fraction, which reflects the huge impact of vitamin D on the human body. There are actually many more effects, and some are so difficult to understand for a person far from medicine that I will not focus on this.

The purpose of today's article was to plant in your mind the value and super-importance of the solar vitamin-hormone D for human health. And it doesn’t matter how old you are, whether you have diabetes or not, and for a diabetic it is especially important to know, it also doesn’t matter what your initial level of health is, because this applies to every human being on the planet.

As you can see, I have long gone beyond diabetes in my articles. Now my recommendations are valuable and useful even for a healthy person, if he wants to live long and healthy. Today I open a series of articles that will be devoted to the "solar miracle".

Follow the news, check your e-mail regularly, wait for my articles, because further information will be even more useful, juicier and tastier. After a while, wait for an article about how much sun we have enough to make up for vitamin D deficiency.

Like the article, share with family and friends. Everyone should know this information! See you!

With warmth and care, endocrinologist Lebedeva Dilyara Ilgizovna