What Is Vitamin D For: A Detailed Overview

Why vitamin D is needed, not everyone knows. But in vain. This element plays a very important role in the body. Unlike other vitamins, vitamin D acts like a hormone and every cell in the body has a receptor for it. Thanks to him, the skeleton is normally formed, immunity increases, blood pressure and heartbeat improve. Vitamin deficiency is manifested by frequent colds, hair loss, depression. About 1 billion people are estimated to have low levels of vitamin D.

But an excess of vitamin does not lead to anything good, so you need to know the norm and check your level. To do this, you need to take special tests. After them, the doctor may prescribe vitamin D supplements. In addition, it is worth diversifying your menu with foods rich in this vitamin. In general, prepare a piece of paper and a pen, then a lot of useful information about vitamin D.

Key Functions of Vitamin D

Vitamin D (calciferol) - two substances that are similar in structure and action: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol or cholecalciferol).

Under the influence of sunlight, vitamin D3 is synthesized in the skin from provitamins (from food and synthesis from cholesterol). In the body, from these two forms (D2, D3), the active product of their transformation, calcitriol, is formed and used. It is formed in two stages: first in the liver and then in the kidneys.

The history of the discovery of vitamin D is connected with the study of retinol, or vitamin A. In the early 20th century, it was found that fish oil is rich in retinol. As an experiment, fish oil was given to dogs. After some time, scientists noticed that the animals stopped suffering from rickets, which was one of the main problems of pediatrics at that time.

About a year later, scientists discovered that when food is exposed to ultraviolet light, the amount of vitamin D in it increases. So it was found that the sun is the source of this valuable element.

The main functions of vitamin D:

• Contributes to the normal formation of the skeleton.

• Provides the exchange of calcium and phosphorus in the body.

• Promotes muscle tone.

• Increases immunity.

• Necessary for the functioning of the thyroid gland and normal blood clotting.

• Helps the body to restore the protective membranes surrounding the nerves.

• Participates in the regulation of blood pressure and heart rate.

• An association of vitamin D deficiency with autoimmune and oncological diseases is suspected and actively investigated.

The main types of vitamin D

Group D vitamins (С27Н44О3) are biologically active substances. According to their structure, they belong to sterols.

The group includes the following elements:

• D1

Chemical formula: C56H88O2

It consists of two components: lumisterol and ergocalciferol. Produced artificially. Does not play a significant role for humans and medicine.

• D2 (ergocalciferol)

Chemical formula: C28H44O

A person can get this element only with food. Also found in bioadditives. Regulates the exchange of calcium and phosphorus in the body.

• D3 (cholecalciferol or colecalciferol)

Chemical formula: C27H44O

Of the entire group, this is the most active substance. Its sources for humans are food (fish, caviar, butter, cheese, chanterelle mushrooms) and sunlight. Even five minutes in direct sunlight can be enough for the body to produce the daily requirement of vitamin D3.

• D4 (dehydrocholesterol)

Chemical formula: C28H46O

Found in the skin. Under the influence of ultraviolet rays, it turns into D3 in the epidermis.

• D5 (sitocalciferol)

Chemical formula: C29H48O

This is a synthetic analogue of vitamin D3, first produced in Chicago. Virtually non-toxic. Used in the treatment of cancer. In nature, it was found in wheat oil.

• D6 (stigmacalciferol)

Chemical formula: C29H46O

The element is still being studied by specialists. It was synthesized from plants.

The exchange of calciferol in the body

In order for vitamin D to start working in the body, it must go through two stages of activation, which will start the mechanism of its action:

• In the liver, the substance interacts with enzymes and turns into calcidiol (25 (OH) D3). It is on the basis of the content of calcitriol in the blood serum that it is determined whether there is enough vitamin D in the body.

• At the second stage, the active form of vitamin D, calcitriol (1.25 (OH) 2D3), is formed in the kidneys. It has a steroid nature.

Calcitriol is responsible for the exchange of phosphate and calcium in the body. In the cells of the intestine, it stimulates the production of a special protein that transports calcium into the blood. And in the urinary tract, it acts on the muscles, increasing the reabsorption of calcium.

After completing its work, vitamin D under the action of enzymes is converted into an inactive substance (the metabolite calcitroic acid), which is excreted from the body along with bile.

The question of the effect of vitamin D on the human body is still open. Scientists continue to study this substance. Perhaps in the near future new discoveries will be associated with it that can improve human life and health.

Interaction with other elements

The human body is a very complex system in which all elements are in constant interaction. And the health and general well-being of a person directly depends on how well-coordinated their work is. The effectiveness of vitamins can be enhanced by "helper molecules", or cofactors. These are small compounds that are involved in biochemical processes. The most significant cofactors that enhance the effects of vitamin D include:

• Calcium. As already mentioned, vitamin D controls the level of calcium in the body. The mineral is well absorbed only with a sufficient amount of calcitriol. Therefore, these two substances are inextricably linked with each other.

• Magnesium. This element performs a lot of functions. For example, it is needed in order for food to be converted into energy. Magnesium is also involved in the absorption of calcium, phosphorus, sodium, potassium and vitamin D. Magnesium deficiency can be replenished not only with the help of supplements, but also by including foods such as spinach, nuts, seeds, whole grains in the diet.

• Vitamin K. This element is responsible for bone health, and also increases blood clotting, so it is simply necessary for the human body. If it is not there, people will begin to die from the slightest injury. Vitamins D and K work together when it comes to proper bone development. Vitamin K can be replenished with foods such as kale, spinach, liver, eggs, and hard cheese.

• Zinc. Multifunctional item. With his participation, the body grows and develops, new cells are formed in it, infections are fought and fats, carbohydrates and proteins are fully absorbed. Zinc also facilitates the absorption of vitamin D and helps calcium get into the bones. A person can get this element along with meat, vegetables and some grains.

   

• Bor. A person needs very little of this substance, but it is still irreplaceable. Boron is involved in the metabolism and absorption of vitamin D. It is found in peanut butter, wine, avocados, raisins, and some leafy vegetables.

• Vitamin A. Controls protein synthesis. Together with vitamin D, it participates in the work of the genetic code. If a person has a lack of retinol, then the functionality of vitamin D will be impaired. Vitamin A is found in carrots, mangoes, liver, butter, cheese and milk. Retinol is a fat-soluble substance and a powerful antioxidant. If it enters the body from plant foods, then it should be combined with fat-containing foods. So retinol will be better absorbed.

The amount of vitamin D in the body

Vitamin D is a vital substance for the human body, so its supply must be controlled. The daily intake depends on the age of the person:

Signs of vitamin D deficiency

In the early 20th century, many children suffered from rickets. This disease develops due to a lack of vitamin D. In adults, with a deficiency of this element, osteoporosis, intestinal obstruction appear, and immunity weakens.

The initial symptoms of vitamin D deficiency include weakness, sweating, irritability, decreased performance and appetite, sleep disturbances, dryness and burning sensation in the mouth.

Due to weakened immunity, a person begins to get sick more often with colds and infectious diseases. Immunity disorders can even lead to the development of autoimmune and oncological pathologies.

With a deficiency of calciferol, a failure occurs in the synthesis of connective tissue, for example, cartilage. From this, a person may experience pain in the joints and spine. Also, with a lack of vitamin D, collagen production is disrupted, and the skin begins to age faster.

Another problem is that when the body lacks calciferol, calcium begins to accumulate in it. Bones become very brittle and break easily, teeth decay.

Causes of vitamin D deficiency in the body

Why is the human body sorely lacking in vitamin D? The reasons are obvious. This vitamin is synthesized in the skin in extremely small quantities and only under the influence of sunlight, but we spend little time in the sun, constantly staying indoors. And even on a long-awaited vacation on a sunny beach, we protect ourselves from UVB rays as much as possible with the help of sunscreens.

Also, vitamin D enters the body with food, but, again, not always in sufficient quantities.

Deficiency of this vitamin is typical for those who suffer from diseases of the kidneys, liver and gallbladder, have problems with digestion due to violations of the intestinal microbial environment (in this case, vitamin D is poorly absorbed from food and is worse converted into an active form).

Fans of soda, dairy products and some other types of food rich in phosphates often experience a lack of vitamins of group D. Excess phosphorus in the body interferes with the full absorption and use of vitamin D.

The human body has about 30 thousand genes, and among them only 2 thousand are affected by vitamin D. However, its deficiency creates a lot of problems: a person can develop various unpleasant diseases, the total number of which exceeds 200. This is a good reason to take care of the optimal level of vitamin D in the body.

Consequences of vitamin D deficiency in the body

• Skin diseases (psoriasis, eczema, etc.), excessive sweating, problems with wound healing. There is clinical evidence that this is due to a lack of vitamin D.

• Partial baldness, hair loss. Correlation of poor hair condition with low levels of vitamin D has been proven for a long time. Moreover, high doses of this vitamin have been successfully used to treat alopecia areata.

• Bleeding gums, more frequent caries, loss of teeth, increased sensitivity of enamel, discomfort in the mouth.

• Weakening of immunity and frequent cases of infection with bacterial and viral infections. If you are constantly sick with SARS and influenza, the reason is most likely a lack of vitamin D. In children, its deficiency manifests itself in frequent pneumonia, bronchitis. In severe cases, an autoimmune disease can even develop.

• Increased fatigue, weakness.

• Problems with the musculoskeletal system: aching pain in the joints, osteoporosis, decreased muscle tone, convulsions.

• Depressive states and other mental disorders. There have been over 600 studies proving their association with vitamin D deficiency.

Thousands of studies have been conducted on the topic of hypovitaminosis D and its consequences, which include preterm labor and fetal growth retardation, rickets in children, cardiovascular disorders, infertility, cancer, erectile dysfunction in men and endometriosis in women, various allergies, thyroid diseases glands, gestational diabetes and type 1 diabetes, autoimmune diseases. Even cavities and obesity are associated with low vitamin D levels!

Consequences of hypervitaminosis (an excess of vitamin D)

An overdose of vitamin D is almost more dangerous than its lack. In Soviet times, it was believed that it was better to have a mild form of rickets than an excess of calciferol.

Hypervitaminosis can be acute or chronic.

The acute form occurs in children if they have been taking high doses of vitamin D for a long time. The condition may worsen due to hypersensitivity to the drug.

The chronic form develops as a result of the use of calciferol in therapeutic doses for a long time, at least six months.

Intoxication with calciferol has three forms, which depend on the severity: mild (without toxicosis), moderate (with moderate toxicosis) and severe (with severe toxicosis).

Light intoxication can pass without a trace. After a severe form, complications can remain for life. Here, calcium deposits on the walls of blood vessels and in internal organs cause the greatest harm. The work of most body systems is disrupted. Children may develop chronic pyelonephritis and improper teething.

In adults, an excess of calciferol leads to an increase in blood pressure and the development of cardiosclerosis, which in turn causes heart rhythm disturbances.

How to know your vitamin D level

To determine the level of vitamin D, they take a special blood test - for 25-OH. Blood is analyzed by high performance liquid chromatography with mass spectrometry (HPLC/MS).

If the result of the analysis was less than 50 ng / ml, this indicates that the body is in great need of vitamin D and is deficient in it. An even lower value, 35 ng / ml or less, indicates problems with the absorption of magnesium, calcium, zinc and other trace elements from food, and if vitamin D drops below 20 ng / ml, this is already a serious deficiency.

Rules for taking vitamin D

Most domestic doctors recommend making up for the lack of this valuable vitamin by taking it in doses of 400-800 IU. But this is too low a dosage, which is unlikely to have a noticeable effect. Even 5000 IU (a prophylactic dose of vitamin D for residents of the regions of the North) is not enough: it only allows you to reach the lower limit of the norm.

With test results above 40 ng, you should take 7000 IU daily for one to one and a half months, and then maintain vitamin levels with a dose of 5000 units.

There are also higher dosages. They are prescribed, in particular, for tuberculosis and autoimmune diseases. Patients should take 30,000-40,000 IU per day for a long period (of course, under medical supervision).

In general, it is quite difficult to correct the situation with a lack of vitamin D in the body in 90% of cases. This vitamin is by no means harmless: long-term use of ultra-high doses (more than 40,000 units) is fraught with toxic effects and overdose. For people with genetic mutations in VDR (a genetic polymorphism of the receptors for this vitamin, which are found in almost every cell of the body), even such gigantic doses do not help at least minimally improve the level of D. They have to take it in the form of injections. The same applies to people with gastrointestinal diseases.

Vitamin D receptors can be activated with the help of gamma-tocotrienols, Omega-3, Resveratrol, curcumin. These drugs work even with VDR mutations.

Foods rich in vitamin D

Among the foods rich in vitamin D, fish is in the lead. Calciferol is also found in whole milk and milk products (cheese, butter), but in smaller quantities and in a form that is difficult to digest.

The main source of vitamin D is fish oil. 100 g of the product contains 250 micrograms of calciferol. This is 2500% of the daily requirement for an adult.

The following is a list of dishes that contain vitamin D. The amount of calciferol in 100 g of the product as a percentage of the daily intake is indicated in brackets:

• Cod liver (1000%).

• Fatty herring (300%).

• Keta (163%).

• Atlantic salmon (110%).

• Pink salmon (109%).

• Black caviar (80%).

• Egg yolk (77%).

• Tuna (57%).

• Chanterelle mushrooms - (53%).

As you can see, among the first - different varieties of fish. It contains more vitamin D than eggs or mushrooms. Therefore, housewives are advised to cook fish dishes for their family more often. So both children and adults will receive the required amount of calciferol.

Below is a summary table of foods that contain vitamin D:

Vitamin D in cosmetology

Vitamin D is a valuable element not only for health, but also for beauty. It is actively used in cosmetology. Vitamin D has a beneficial effect on the skin and hair, nourishing and rejuvenating them. There are many recipes for various masks with calciferol, below are the most popular and most effective of them:

• Fish oil face masks

This recipe is especially relevant for aging and dry skin. It is necessary to mix 1 tablespoon of yeast, 1 tablespoon of sour cream, 1 teaspoon of fish oil and the same amount of honey. Put the resulting slurry in a water bath until it begins to ferment. Then apply the mixture on the face and neck and leave for 10 minutes. After the end of the exposure time, rinse with warm water.

The following mask is suitable for all skin types. Her recipe is not simple, but effective: you need to mix 1 teaspoon of eggshell powder, 1 teaspoon of fish oil, 1 egg yolk, 2 teaspoons of mustard honey and half a glass of boiled pumpkin pulp. The mask is applied to the skin warm and left for 1-15 minutes, after which it must be washed off with water.

• Face masks with egg

You can choose a recipe for any age and skin type. For example, for aging skin, it is recommended to mix 1 tablespoon of crushed dried lemon peel, 1 egg yolk and 1 teaspoon of olive oil. For any skin, the following recipe is suitable: 2 proteins, 1 tablespoon honey, half a teaspoon of almond oil and 2 tablespoons of oatmeal. This mask perfectly nourishes and has a slight whitening effect. Dry aging skin can be nourished with a mixture of 1 tablespoon of banana puree, 1 egg yolk, 1 tablespoon of sour cream and honey.

If you need to get rid of wrinkles, it is recommended to take 1 yolk, 1 teaspoon of vegetable oil and 1 teaspoon of aloe juice. Previously, aloe leaves must be kept in the refrigerator for 2 weeks.

Oily skin with enlarged pores will be saved by a mask of 2 tablespoons of cottage cheese, half a teaspoon of liquid honey and one egg.

For skin whitening, it is recommended to mix half a glass of carrot juice, 1 teaspoon of potato starch and half a raw egg yolk. The mask is applied to the skin for 30 minutes, then washed off in a contrasting way: alternately with cold and hot water.

• Vitamin D masks for hair and scalp

Most often, masks with an egg or only with yolk are used for hair. For hair growth, use a mask consisting of 1 tablespoon of lemon juice, 1 tablespoon of onion juice and 1 egg yolk. The mixture is applied to the head two hours before washing and left. It is recommended to carry out the procedure once a week.

For dry hair, mix 2 egg yolks, 2 tablespoons of burdock oil and 1 teaspoon of calendula tincture.

To get rid of dandruff and strengthen the roots, this mask is used: 1 tablespoon of crushed plantain leaves, the same amount of burdock, 2 tablespoons of aloe juice and 1 egg yolk.

To shine and strengthen hair, mix 1 tablespoon of honey, 1 tablespoon of castor oil, 1 egg yolk and 1 tablespoon of cognac.

When you want to restore dry and damaged hair, take 2 yolks, 1 tablespoon of hazelnut oil and a drop of lemon essential oil.