Why do children need vitamin D and does everyone need it?
Modern research has repeatedly proven that vitamin D (calciferol) is involved in many chemical processes in the body. According to the most conservative estimates, there are more than 30 of them. Let’s list the most global ones.
So, vitamin D:
- helps to absorb calcium and phosphorus, which is necessary for the growth and harmonious development of the child;
- helps strengthen bone, muscle tissue, tendons and ligaments;
- increases the body's resistance to viral infections;
- affects general condition and mood;
- necessary for the proper functioning of the heart and blood vessels, pancreas and other internal organs;
- participates in the production of sex hormones and the functioning of the reproductive system.
Chronic deficiency of this substance in children at an early age significantly increases the risk of developing serious diseases in the future: diabetes, obesity, psoriasis, problems with the intestines and cardiovascular system, autoimmune diseases and cancer.
It is obvious that a growing child’s body simply needs additional vitamin D. Especially babies. The fact is that babies under 1 year of age have practically no opportunity to obtain this valuable vitamin naturally. During walks, they usually lie in the stroller, so the sun hits their cheeks at best. And in bad weather, mothers even hide their babies under a visor or hood. Babies will also begin to receive fatty fish and other foods rich in vitamin D only after 1 year. So preventive care is mandatory for all children of this age.
As a rule, vitamin D continues to be recommended for older children. Yes, they are in the sun more often and their menu is varied, but still this is not enough, especially in the period from October to April, when there are objectively few sunny days. Since the main territory of our country is located in a zone of insufficient insolation, vitamin D in a preventive dosage will be useful not only for children, but also for adults. Moreover, residents of the southern regions of the country need it only in the autumn-winter period, and the northern regions need it all year round.
Main types of vitamin D
Vitamins of group D (C27H44O3) are biologically active substances. According to their structure they are classified as sterols.
The group includes the following elements:
- D1
Chemical Formula: C56H88O2
Consists of two components: lumisterol and ergocalciferol. It is produced artificially. Does not play a significant role for humans and medicine.
- D 2
(ergocalciferol)
Chemical formula: C28H44O
A person can receive this element only through food. Also found in dietary supplements. 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 of direct sunlight can be enough for the body to produce its daily requirement of vitamin D3.
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- D4
(dehydrocholesterol)
Chemical formula: C28H46O
Contained 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. It was found in nature in wheat oil.
- D6
(stigmacalciferol)
Chemical formula: C29H46O
The element is still being studied by specialists. It was synthesized from plants.
How to understand that your body lacks vitamin D
In children of the first year of life, the lack of calciferol manifests itself very clearly. These are primarily various deformations of the head and legs - the so-called wheel legs or X-shaped legs. In older children, symptoms of vitamin D deficiency, in addition to those listed, may include frequent colds (more than once a month), very mobile joints - when the knees seem to look backward or the fingers bend very easily in all directions. For schoolchildren and adults, typical symptoms also include fatigue, apathy, frequent depressed mood, muscle cramps, and deterioration in the condition of hair and nails.
Ekaterina Volkova:
“The simplest test: answer the question whether you are taking vitamin D preventatively. If not, you probably have a deficiency. This is confirmed both by the experience of my patients and the data of my colleagues.”
Risk factors for the development of vitamin deficiency
Let's look at the main reasons why vitamin deficiency may occur:
- Vegetarianism, dieting.
- Limited exposure to sunlight.
- Dark skin color.
- Limited sleep, night shifts.
- Living in environmentally unsafe areas.
- Chronic gastrointestinal diseases.
If we take into account possible dietary errors and infrequent exposure to the sun, it becomes clear that there is a risk of vitamin D deficiency in a large percentage of people (both children and adults).
How much vitamin D should children and adults drink per day?
The preventative dosage of vitamin D is 1000 IU (international units) per day. Children from 0 to 6 months are usually prescribed 500 IU per day. Depending on the drug, this may be 1, 2 or more drops. Read the instructions carefully before use and follow the dosage.
In some cases, the dose may be increased to 2000 IU for children and up to 10,000 IU for adults. However, such a regimen should be prescribed by a doctor and only based on the results of a blood test and a complete diagnosis of the body. As a rule, increased doses are taken for a course of no more than 6 months, after which you need to take another test for control.
– The official norm is 30–100 ng/ml of vitamin D in the blood. But since the range is too large, it is better to focus on the average value - from 50–60 ng/ml and above. With such indicators, the body feels noticeably better than with the minimum norm.
Calciferol content in organs, tissues and skin
Small amounts of vitamin D are found in foods (fat, fish liver, egg yolk), but most of the vitamin D used in the synthesis of calciferol is formed in the Malpighian layer of the epidermis from 7-dehydrocholesterol during a non-enzymatic, ultraviolet light-dependent photolysis reaction . The activity of the process is directly dependent on the intensity of irradiation and inversely dependent on the degree of skin pigmentation. With age, the content of 7-dehydrocholesterol in the epidermis decreases, which may be directly related to the development of a negative calcium balance in old people.
Can there be an overdose of vitamin D?
There are no clinically proven cases of vitamin D overdose. So, if a child gets an extra drop in a single dose, nothing bad will happen. But if you or your child is taking calciferol in doses higher than prophylactic doses, it is recommended that you monitor your blood levels every 6 to 12 months so that your dosage can be adjusted when needed.
Accumulation places
The action of calciferol at the cellular level is similar to the action of other steroid hormones. In studies conducted with radioactive calciferol, it was shown that it accumulates in the nucleus of cells of the intestinal villi and crypts, as well as osteoblasts and cells of the distal renal tubules.
In addition, it was found in the nuclei of cells that were not expected to be the target cells of calciferol. We are talking about the cells of the Malpighian layer of the skin and, testes, placenta, uterus, mammary glands, thymus, precursor cells of the myeloid series. Binding of calciferol was also found in the cells of the parathyroid glands, which is extremely interesting, as it indicates the possible participation of calciferol in the regulation of parathyroid hormone (PTH) metabolism.
The calciferol receptor is a protein present in intestinal cells with a molecular weight of 90,000-100,000, which binds calciferol with high affinity and low capacity. Binding is saturable, specific and reversible. Thus, this protein meets the basic criteria characterizing the receptor. It is found in many tissues where vitamin D accumulates (see sites of accumulation). If physiological concentrations of salts are used in the analysis, then most of the unoccupied receptor is detected in the nucleus in the form associated with chromatin. This is similar to the location of the receptors for most steroid hormones, such as progesterone and T3. It remains unclear whether prior activation of the calciferol-receptor complex is required for binding to chromatin, as is the case with typical steroid-receptor complexes.
How to take vitamin D correctly and which is better - oil solution or water solution
Pharmacies and stores offer a large selection of different forms of vitamin D: drops and capsules, dragees, ampoules, chewable tablets. Oil and water solutions are fundamentally different in composition and consistency. These are the questions parents most often ask about. It is a very popular opinion that the only effective form of vitamin D is an oil solution, since the vitamin itself is fat-soluble. However, this is not quite true. It all depends on the age of the patient.
To assimilate the oil solution, full functioning of the enzyme systems of the gastrointestinal tract is required. Therefore, for example, an aqueous solution is better suited for children in the first year of life - it is absorbed faster. It is convenient and safe to give to babies and can be drunk at any time of the day without being tied to a specific meal.
The disadvantage of water-based drops is that their main component begins to degrade in the oral cavity and stomach under the influence of hydrochloric acid, while vitamin D is absorbed in the small intestine. Therefore, adults are recommended to choose capsules - they are more effective. An oil solution is also good, but it is better absorbed if taken at the same time as food. The same applies to capsules, so the ideal time to take vitamin D is in the morning during breakfast.
And, of course, be sure to include in your diet foods high in this essential vitamin: fatty fish, cod liver, egg yolk, butter, goat milk, hard cheeses. And in the summer, try to spend more time outdoors, not forgetting about sun safety rules.
Health to you and your children!
This material summarizes evidence-based medicine studies from different years. However, it is for informational purposes only and cannot be used as a direct guide to action. Before consuming vitamin D, you should consult a specialist.
Admission rules
You should take the pharmacy vitamin strictly following the instructions, namely:
- The drug is taken in the morning or at lunch (first half of the day), since it can actively affect the nervous system and cause overexcitation and insomnia. This point especially applies to children.
- Since vitamin D is classified as a fat-soluble vitamin, you need to eat something fatty along with the pill. So he will assimilate well.
- Separate intake of vitamins D and E is indicated, since their combined use reduces the absorption of both.
- Calcium and another vitamin K are well absorbed along with vitamin D. It is not at all necessary that the intake take place at the same time, the body simply must receive a daily dose of all of the listed substances.
Transport of calcium and phosphate from the intestine
When transferring calcium and phosphate ions through the intestinal mucosa, the following is necessary:
1) capture and transfer of brush border and microvilli through the membrane,
2) transport through the membrane of mucosal cells,
3) excretion through the basal lateral membrane into the extracellular fluid.
It is clear that calciferol activates one or more of these steps, but the specific mechanism of its action has not been established. It was assumed that CSB was directly involved in this, but subsequently it was shown that calcium transfer occurs 1-2 hours after the administration of calciferol, i.e. long before the increase in CBP concentration in response to calciferol. Probably, CSB, by binding calcium, protects mucosal cells from it during periods of active transport of this ion. Some researchers continue to search for proteins that may be involved in calcium transport, while others believe that this process, especially the initial increase in calcium current, may be mediated by changes in membrane charge and the effect of vitamin D on energy production in the mitochondria of mucosal cells.
