Vitamin D - everything about it, benefits and harm, slowing down aging

November 13, 2020 Roman Zabolotnikov Home page » Drugs to prolong life Views:

Are you sure you have enough Vitamin D?

Today we will talk about vitamin D , its benefits for health and longevity, according to Ray Kurzweil - Google and famous immortalist and futurologist - it is one of the top 3 main anti-aging drugs available today. In this article, I will detail the scientific research on vitamin D that supports this claim and its practical applications.

Vitamin D deficiency

Many people have heard of vitamin D and know that it is produced in human skin when exposed to sunlight. This is the only vitamin that is produced in this way in the human body. Vitamin D can be taken externally through food or medications. According to statistics, its deficiency is observed in a very large percentage of the population of the entire planet - most of all among residents of northern countries; in the world, more than a billion people lack this vitamin! Even in countries with sufficient sun intensity - India, Pakistan, China - there is a shortage of it. The territory of Russia is located in such a way that it is poorly exposed to solar radiation - therefore Russians have a very high risk of getting vitamin D .

The need for vitamin D increases in people who drink a lot of tea and coffee.

How does vitamin D work?

Vitamin D is the general group name for five substances that have the activity and properties of sterols. These substances are called vitamin D vitamers. That is, each vitamer is, in fact, a type of vitamin D. So, the following vitamers are currently classified as vitamin D:

1. Vitamin D2 – ergocalciferol; 2. Vitamin D3 – cholecalciferol; 3. Vitamin D4 – dehydrocholesterol; 4. Vitamin D5 – sitocalciferol; 5. Vitamin D6 – stigmacalciferol.

Vitamin D1 does not occur in nature and can only be obtained through chemical synthesis. Ergocalciferol is a synthetic vitamin D2 produced by the action of ultraviolet radiation on certain types of fungi. Vitamin D2 is used as an additive in various finished products, such as bread, infant formula, and so on. Ergocalciferol enriches the food product, providing the human body with a normal daily dosage of vitamin D.

Cholecalciferol is a natural vitamin D3 that is found in various foods of animal origin, that is, it enters the human body through consumption of animal products.
Dehydrocholesterol is a precursor or provitamin for D3 (cholecalciferol). Normally, human skin contains dehydrocholesterol, from which vitamin D3 (cholecalciferol) is synthesized under the influence of sunlight.
Sitocalciferol is a vitamin D5 found in wheat grains.
Stigmacalciferol is found in some plants.

The two most biologically active forms of vitamin D are ergocalciferol and cholecalciferol, which a person can obtain from food or synthesize in the skin using ultraviolet light. Other forms of the vitamin have relatively low biological activity. Since the functions of all forms of vitamin D are the same, and they differ only in the method of production and activity, they are usually not separated in medical and popular science articles.

Vitamin D is more of a "prohormone" than a vitamin . It consists of ferols that become active under ultraviolet irradiation. In the body, this process takes place in the skin. It is necessary to ensure the functioning of almost all organs and systems of the human body. Each of us knows from childhood that vitamin D is needed to prevent rickets and other bone diseases. But in the last 30 years, scientists have focused on studying the so-called “extraosseous effect of vitamin D.” Thanks to these studies, it has been proven that vitamin D is present in many tissues of our body, for example, in immune and myeloid cells, in the adrenal cortex, in adipose tissue cells, large intestine, cardiomyocytes, skin, dendrites of cells of the central nervous system and many others.

Therefore, vitamin D has the broadest extraosseous or non-classical effects. A huge number of studies published in recent years have focused on how important vitamin D intake is for the prevention of a wide variety of pathologies. Dozens of meta-analyses have been made on the prevention and treatment of diseases of the immune, cognitive, reproductive functions, diseases of the endocrine system, cardiovascular pathology, tuberculosis, viral hepatitis, diabetes mellitus, obesity, cancer and other pathologies arising from vitamin D deficiency.

Firstly, it is vitamin D that is responsible for the high-quality and effective functioning of our immunity - innate and acquired. The fact is that it activates protective killer cells, whose task is to search for and destroy viruses and bacteria.

Secondly, it was found that vitamin D is involved in the production of dopamine - the hormone of joy and pleasure , so its lack often leads to apathy, bad mood and even depression.

By controlling the optimal level of calcium in the blood, it helps the nervous system work without interruption, and the muscles maintain strength and tone ! With a deficiency of vitamin D, our strength is “zero” and chronic fatigue is a constant companion even on weekends and on vacation.

Vitamin D is a real assistant for schoolchildren, students and office workers, because it helps improve memory and concentration .

The “sunshine vitamin” also has a great influence on the pancreas, or more precisely on the synthesis of insulin and regulation of blood sugar . And in women it also stimulates the production of sex hormones , which has a beneficial effect on the ability to conceive.

And finally, vitamin D slows down the aging process :

- stimulates autophagy. This mechanism underlies low-calorie nutrition - the most reliable and studied method of life extension;

- increases the length of telomeres. Telomeres directly limit human lifespan;

Vitamin D deficiency diseases

Vitamin D deficiency seriously affects health - children with a lack of this vitamin can develop diseases: rickets, and vitamin deficiency, which will cause hair loss, peeling skin, and growth can be greatly reduced. In adults, deficiency can lead to even more serious health problems, and cause the following diseases:

Osteoporosis
Type 2 diabetes
Hypertension and disorders of the cardiovascular system
Multiple sclerosis and Parkinson's disease
Depression and frequent headaches
Breast and ovarian cancer in women

Why do you need vitamin D supplements?

It is generally accepted that if a person spends a lot of time in direct sunlight, he is not at risk of vitamin D deficiency. However, there are many obstacles to the entry of calciferol into the body. Let's name the main ones.

The amount of melanin in the skin. Over the same period of time, dark skin produces 2 times less vitamin D than light skin. Moreover: dark pigmentation of the skin can cause a complete cessation of the production of the sun vitamin in the body. The thing is that the skin pigment melanin (namely, it is responsible for skin color) has the ability to effectively compete with cholecalciferol for ultraviolet rays.
Age characteristics of the body. Vitamin D is formed in the deep inner layer of the skin from its predecessor, provitamin D. With age, the content of this provitamin in the skin decreases, followed by a deterioration in the body’s ability to independently produce the sun vitamin.
Living in areas above 35º north latitude. The further away the area is from the equator, the longer the waves of ultraviolet radiation, the less sun hits the skin and the less vitamin D is produced.
Obesity. Adipose tissue is able to take part of calciferol and increase the amount of inactive forms of the vitamin. Moreover, the relationship between the amount of fat in the body and vitamin D deficiency appears only in women.
Clothing, sunscreen, glass (eg window). All these items prevent the sun's rays from reaching the skin. There is evidence that sunscreen with a protection factor (SPF) of 8 to 15 reduces the synthesis of the sun vitamin by 95-98%.
Commitment to a vegetarian diet. Animal foods are another important source of vitamin D.
Impaired absorption function of the gastrointestinal tract.

A person cannot reliably know whether enough calciferol was produced in his skin and entered the body with food. Moreover, ultraviolet radiation is a carcinogenic factor that can provoke the development of skin cancer. Therefore, it is very important to take vitamin D supplements. Which ones should you prefer and why?

What are the benefits of vitamin D?

Ray Kurzweil

If you increase vitamin D in your blood, firstly, you will not get all of these diseases, and secondly, you will be able to feel better due to the slowing down of the aging process by this vitamin. Ray Kurzweil , a well-known personality - the technical director of Google, one of the most famous supporters of the ideas of life extension, transhumanism and immortalism, recommends it as the most important geroprotector for slowing down aging, which is in the top 3 that he takes himself.

Vitamin D - slows down aging

Vitamin D helps activate autophagy processes in the cells of your body; for the study of autophagy processes in the body, they were given the Nobel Prize in Medicine in 2020, you can read more in this article.

Links to scientific research on vitamin D activation of autophagy to slow aging.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3679232/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3285235/
https://www.ncbi.nlm.nih.gov/pubmed/20557314
https://www.ncbi.nlm.nih.gov/pubmed/20488750

Vitamin D promotes the activation of telomerase, which in turn can restore the terminal sections of telomere DNA - thereby slowing down aging.

Delays the development of age-related diseases:

Type 2 diabetes
The whole complex of cardiovascular diseases
Autoimmune diseases
Prevents age-related dementia
Fights cancer
Helps in restoring immunity

What foods contain vitamin D?

Vitamin D is found in fatty fish and fish oil and contains approximately 400 IU (international units) per teaspoon. To get enough vitamin D from foods - at least 500 IU you need to eat 200 grams of salmon per day, or more than a kilogram of cod - few people consume this amount of fish per day.

A small amount of vitamin D is also found in butter, cheese, liver, cream and full-fat milk, in egg yolks, fish roe, some mushrooms, in all these products the vitamin D content is so minimal that they cannot compensate for the body's need, for example, 100 grams of butter contains - 35 IU, 100 grams of egg yolk - 25, liver - 50 IU.

Vitamin D cod liver

There is one product quite rich in vitamin D - cod liver (mostly available in canned form), it contains a very large amount of it, if you constantly eat cod liver, you can easily get an overdose of this vitamin, cod liver cannot be stored for a long time, and eat in large quantities - to get the daily requirement of vitamin D, it is enough to eat a small piece - 20-30 grams. We can recommend purchasing 1 can of cod liver for a family of 3-4 people, and eating it within a maximum of 2-3 days, then you won’t have to worry about a lack of vitamin D in the body. The main thing: do not leave an open jar of liver in the refrigerator for a long time, this product spoils very quickly and can ultimately harm you.

Recommended Vitamin D Intake

Vitamin D intake can be measured in 2 ways: in micrograms (mag or mcg) and international units (IU). 1 microgram of vitamin D is equal to 40 IU of vitamin D. Recommended lifetime intakes of vitamin D were revised and updated by the American Institutes of Medicine (IOM) in 2010 and are currently set as follows:

- infants-0-12 months - 400 IU (10 mcg)

-children - 1 - 18 years - 600 IU (15 mcg)

— adults up to 70 years old -600 IU (15 mcg)

- adults over 70 years old - 800 IU (20 mcg)

- pregnant or lactating women - 600 IU (15 mcg)

Although the body can produce vitamin D on its own, there are many reasons why vitamin D deficiency occurs. Darker skin pigments and the use of sunscreens can significantly reduce the body's ability to absorb ultraviolet B (UVB) rays needed to produce vitamin D.

Sunscreen with a sun protection factor (SPF) of 30 can reduce the body's ability to synthesize the vitamin by 95%. In order for vitamin D production to begin, a person's skin must be directly exposed to sunlight and not hidden under clothing. Even the angle at which the sun's rays hit the Earth can affect their absorption.

People who live in northern latitudes or areas of high pollution, work at night and stay home during the day, or have to stay indoors all the time should try to get extra vitamin D from their diet whenever possible. Infants who are exclusively breastfed are also at high risk of vitamin D deficiency, especially if they are dark-skinned or have minimal exposure to sunlight. The American Academy of Pediatrics recommends that all breastfed infants receive approximately 400 IU of vitamin D by mouth daily.

Vitamin D supplements are widely available, but it's best to get any vitamin or mineral directly from natural sources. It is not a single vitamin or mineral alone that makes certain foods an important part of our diet, but the combined actions of food nutrients working together to further ensure greater absorption and assimilation.

For example, vitamin D is fat soluble. This means that its absorption requires dietary fat. In addition, magnesium is needed to convert vitamin D into its active form.

It has been proven time and time again that consuming certain nutrients in supplement form will not provide the same health benefits as consuming nutrients from whole foods. You should first be focused on getting your daily required amount of vitamin D from sunlight and foods, and then use supplements as backup.

Recent Developments Regarding Vitamin D Intake from MNT News

High levels of vitamin D in the blood, the researchers found, protected even healthy people at the genetic level.

Researchers from Boston University School of Medicine found that higher levels of vitamin D in healthy people had a significant positive effect on genes that are involved in several biological processes associated with disease, including cancer, autoimmune disease, cardiovascular disease and infectious diseases.

How to take vitamin D to slow down aging?

To slow down aging, you need to consume from 500 to 1000 IU (vitamin D bioavailability ranges from 60–90%) depending on the time of year and time spent in the sun, as well as age. In the summer, it is necessary to reduce your vitamin D intake if you spend a lot of time outside the house, exposing your skin to sunlight - although it is also not recommended to overdo it, since solar radiation causes accelerated aging of the skin - photoaging, which I wrote about in the article.

My course of taking vitamin D : I’ll give an example of my own course of admission: in the summer I don’t take vitamin D at all, I start taking vitamin D in September, in a dosage of 1000 IU to 5000 IU (I eat few foods rich in vitamin D) and take approx. 3-4 months (until December), after that I take a month-long break and then resume taking it until I begin to be outside more often, in the sun more often (I take a month-long break just in case, since the analysis is expensive and I don’t do it often it will work).

Russian pharmacies sell a cheap drug to slow down aging - aquadetrim (cholecalciferol), its price is about 200 rubles, and the package is enough for several months of use. Aquadetrim contains vitamin D in liquid form, 1 drop contains 500 IU of vitamin D, it is recommended to take it with a small amount of water in a tablespoon, preferably on an empty stomach. It looks like just a clear liquid.

Vitamin D and Vitamin A

The term "vitamin A" refers to another group of fat-soluble compounds that promote growth and development, reproduction, immune system function, vision, skin health and gene expression.

Because fat-soluble vitamins can accumulate in the body, they can reach toxic levels. And here's what's interesting: it turns out that vitamin A can prevent vitamin D toxicity, and vice versa.

Minimum and acceptable dosages of vitamin D

Vitamin D dosage table (taken throughout the day) based on Wikipedia data. Different countries consider the acceptable dosage to be different, but more and more studies show that there should be as much vitamin D in the blood as possible.

As you can see from the table, with age, our body needs more and more vitamin D - this happens on the one hand due to the deterioration of its absorption in the intestines due to the age-related deterioration in the composition of the microflora, but also because with age people become less active - They walk less and spend less time in the sun. These facts must be taken into account when determining the dosages required for use.

Norm per day

How much of this substance is required for the average person per day? On average - from 2.5 to 5 mcg. But even this average dose increases significantly under the following conditions:

if a person does not go to the sun;
“sits” on a strict diet;
is over 60 years of age (10 mcg);
lives in northern latitudes;
grows rapidly (15-20 mcg);
in women during lactation and pregnancy (25 mcg);
for bodybuilders and professional athletes (120 mcg)

An important point: it is important to combine treatment with doses of vitamin D with doses of ascorbic acid and retinol (vitamin A).

Vitamin D, what is it and how much should you take per day on video:

Overdose Harm: Too Much Vitamin D

The main thing with vitamin D is not to overdo it, as if there is too much it can negatively affect your health. With an excess, calcification of the arteries can develop, their stiffness increases, which can cause diseases of the cardiovascular system, and can provoke the formation of kidney stones. An overdose of vitamin D does not happen overnight; most often it can occur with excessive consumption of the vitamin over a long period of time - a month or more.

This study describes the risks of taking too much of the vitamin:

https://ndt.oxfordjournals.org/content/early/2012/03/18/ndt.gfs046.full

There is evidence that too low and too high dosages can affect male reproductive function https://ncbi.nlm.nih.gov/pubmed/26991835

The optimal norm of vitamin D in the blood is considered to be a level from 30 ng/ml to 60-70 ng/ml, which can be determined by doing a test (the test is called 25-OH vitamin D) - unfortunately, tests for vitamins are not included in the list of free medicine, so All that remains is to use the services of paid laboratories, where such an analysis costs from 1 thousand rubles.

Vitamin D and Vitamin K

The “K” in vitamin K comes from the German word “koagulation.” Coagulation is the process of formation of a blood clot. That is, vitamin K plays a key role in the blood clotting process.

In simple terms, vitamin K allows the body to use calcium to perform clotting functions. If there is not enough vitamin K, the body cannot use calcium for this purpose, and therefore the blood does not thicken.

In addition to its role in clotting, vitamin K is also involved in the formation and maintenance of bones and teeth. It does this by activating a protein called osteocalcin, which helps the body use calcium and deposit it where it needs to be.

In other words, there is a very strong connection between calcium and vitamin K in that vitamin K helps in the proper use of calcium. And if you have a vitamin K deficiency, calcium levels can build up and be deposited in soft tissue.

People with low vitamin K levels are more likely to suffer from atherosclerosis, or calcification of the arteries. And people with high levels of vitamin K (especially vitamin K2) seem to suffer less from it.

In fact, studies in rats have shown that supplementation with vitamin K2 (but not K1) not only inhibits arterial calcification, but can also remove 30-50% of the calcium that has already been deposited. Unfortunately, this magical effect has not yet manifested itself in humans.

In general, vitamin D increases calcium levels in the body. Vitamin K helps the body use calcium. Therefore, if you decide to supplement your diet with a high dose of vitamin D when you are deficient in vitamin K, the long-term results could be disastrous.

Symptoms of vitamin D overdose:

Digestive disorders: nausea, diarrhea, or the opposite symptoms such as lack of appetite, constipation.
Sometimes it becomes more difficult to breathe, shortness of breath appears during physical activity
Muscle pain, headaches, joint pain
Convulsive conditions
Fever
Pressure surges

If an overdose is suspected, the drug must be discontinued immediately and monitored to see if the symptoms disappear, and if they do not disappear, then do a test to determine the vitamin content in the blood. An overdose of this vitamin is very rare.

The combination of vitamins D and K and a review of IHERB drugs

Vitamin D and K

A very good and inexpensive vitamin D, which can help quickly raise its level in the blood, can be purchased on IHERB using the link. A dosage of 5000 IU is suitable for you if it is in your blood in a value of up to 20 ng/ml, as the practice of my clients shows - this happens quite often.

The combination of these two vitamins can provide significant health benefits to the body; they form a synergistic complex. Vitamin K controls the calcium balance in the body: it counteracts the deposition of calcium in the walls of the arteries, directing it to its destination - in bones, teeth and nails, and also has many beneficial properties against aging, and even preventing cancer, but its consideration requires a separate article.

Life Extension Life Extension Foundation sells a complex preparation containing vitamin D and K, as well as marine iodine - a good combination, you can buy it via the link using my referral code ZPW509 and get a 10% discount on it.

Conclusions: I looked at benefits of vitamin D , and its use for slowing down aging and achieving longevity, this is one of the few geroprotectors for slowing down aging that can be purchased in a regular pharmacy at a minimal price, I think? It's worth taking advantage of this. Thank you for reading the article, leave comments, ask questions, I will be glad to answer.

Can everyone get vitamin D?

The instructions for cholecalciferol preparations contain specific contraindications: vitamin D is prohibited in case of individual intolerance and any condition of the body that is accompanied by an increase in calcium levels in the blood and urine. All serious side effects from an overdose of the “solar cell” are associated with hypercalcemia. This condition is fraught with serious consequences and can even lead to death (hypervitaminosis is especially dangerous for young children).

Therefore, before using native calciferol preparations, you should consult a doctor and weigh the pros and cons. The doctor will determine whether a particular person can take vitamin D and in what dosage. A blood test for total 25 (OH)D (25-hydroxycalciferol) and a comprehensive examination of the body will help you reach a verdict. To exclude conditions and diseases that may be a contraindication to taking cholecalciferol, the following examinations are prescribed:

determination of calcium and phosphorus in blood and urine;
X-rays of light;
Ultrasound of the kidneys, liver and thyroid gland;
ECG;
general clinical tests and blood biochemistry;
determination of thyroid and parathyroid hormones (parathyroid hormone);
identification of mutations in the VRD gene, which encodes vitamin D receptors.

According to indications, additional methods are prescribed (endoscopic examination of the digestive tract, x-ray of bones, etc.). If contraindications to the administration of cholecalciferol are identified, the situation is resolved on an individual basis.

Side effects of vitamin D

Calciferol is a natural substance for the body. Therefore, there cannot be much of this vitamin if it comes from food or is synthesized by the skin. Excess and side effects of the “solar element” are primarily associated with taking medications containing its active metabolites – calcitriol and alfacalcidol. The latter are prescribed for the treatment of osteoporosis and a number of other diseases and in patients with impaired metabolism of calciferol in the body to correct its deficiency.

Native vitamin D preparations, even in large dosages (several thousand IU), rarely lead to an excess of the active substance and negative consequences. Overdose and side effects in adults are possible in the following cases:

taking doses that exceed 4000-10000 IU for more than half a year;
individual characteristics of a person (sensitivity of receptors to calcitriol, mutation of the VRD gene, metabolic disorder of the “solar element” in the body, etc.);
concomitant diseases (thyrotoxicosis, malignant tumors, bone metastases, etc.).

In infants, the likelihood of intoxication with calciferol is an order of magnitude higher, since their body is not fully formed and some biochemical reactions may occur with disturbances. Therefore, even ordinary prophylactic doses can sometimes cause side effects. This is especially true for babies who were born premature or with developmental defects.

According to the official instructions for cholecalciferol (VIDAL drug directory), the drug has the following side effects:

anorexia (lack of appetite);
nausea and vomiting;
weight loss;
pronounced thirst;
polyuria;
cephalgia;
pain in muscles, joints and bones;
irritability;
depression;
disruption of the heart;
formation of kidney stones;
nephrocalcinosis, calcification of soft tissues and other structures of the body.

All negative symptoms are in one way or another caused by hypercalcemia and hypercalciuria. The longer this condition lasts, the more serious changes occur in the body. The deposition of calcium salts in blood vessels and internal organs can lead to multiple organ failure and human death. If a child has suffered hypercalcemia, this negatively affects his subsequent physical and mental development. The specific outcome depends on the level of calcium in the blood and how long it remains in the general bloodstream.

Symptoms of vitamin D overdose

The clinical picture of an overdose of calciferol will vary depending on the level of calcium in the blood, the severity of the changes that occur and the general condition of the person. Acute poisoning with products containing vitamin D or its active metabolites is characterized by severe intoxication of the body. Repeated vomiting, increased body temperature, general malaise and other typical symptoms may occur.

Chronic poisoning may be asymptomatic or accompanied by complaints:

discomfort, pain in muscles, bones and joints, muscle cramps;
headaches and dizziness, up to “turning off” consciousness;
emotional lability, apathy, insomnia, lethargy, memory loss, etc.;
dyspeptic disorders;
problems with the heart and blood vessels (red eye symptoms, heart rhythm disturbances, blood pressure surges);
hormonal imbalances;
skin itching;
disruption of the genitourinary system (swelling, frequent urination, etc.).

With prolonged overdose, children begin to lag behind in development, their behavior changes.

Treatment of vitamin D overdose

In case of acute intoxication, hospitalization in a specialized department is indicated. Young children are also treated in hospital. Chronic overdose of calciferol in adults, without significant changes, requires outpatient observation. To eliminate excess nutrients, cancel all dietary supplements and medications containing it.

In case of acute hypercalcemia, forced diuresis is carried out for 4 hours: saline solution is injected into the vein at the rate of 20 ml/kg and furosemide (or any other loop diuretic) – 1 mg/kg. Calcitonin (4 units/kg every 12 hours), bisphosphonates, glucocorticoids, and other medications may be added. This is followed by symptomatic treatment aimed at eliminating the effects of hypercalcemia.

Contraindications for taking vitamin D

Even if a person is absolutely healthy and plans to take dietary supplements with cholecalciferol for preventive purposes, it is advisable to first consult with a doctor, donate blood for calcium and 25 (OH)D. Any prescriptions for children are made by a pediatrician, also after tests. Contraindications may include hypoxia and intracranial birth trauma, nuclear jaundice, small size of the large fontanelle and other factors assessed by the pediatrician.

Considering the fact that almost all the negative consequences of taking products containing the “solar element” are associated with hypercalcemia, first of all, people who have high calcium in the blood should not take vitamin D. The reasons for this condition may be the following:

associated with increased production of parathyroid hormone: primary hyperparathyroidism due to a tumor or multiple endocrine neoplasia (Zollinger-Ellison syndrome, pituitary neoplasms, cellular formations of pancreatic islets, pheochromocytoma, medullary thyroid carcinoma); familial hypocalciuric hypercalcemia; lithium therapy;
associated with malignant processes: solid type tumors with humoral mediated hypercalcemia (kidneys, lungs); solid neoplasms with metastases (breast, prostate); hematological oncological diseases (leukemia, lymphoma, multiple myeloma);
caused by an increased rate of calcium metabolism in bone tissue: thyrotoxicosis; long-term immobilization; long-term use of thiazide diuretics; excess vitamin A;
resulting from renal failure: aluminum intoxication; severe secondary hyperparathyroidism;
related to vitamin D: calciferol intoxication; increase in blood calcitriol; granulomatous diseases; idiopathic hypercalcemia of infants.

If a person initially has an increased level of calcium in the blood, or there are deposits of its salts in the structures of the body, then taking medications with vitamin D is contraindicated for him. Also a limitation will be individual increased sensitivity to the “solar element”, peculiarities of calciferol metabolism in the body (poor absorption due to malabsorption syndrome, etc.) or an increase in phosphates in the blood and urine. If a person is allergic, then before starting therapy, the possibility of allergic reactions to additional components is taken into account... [read full version]