Vitamin D or calciferol performs the most important functions in the human body: it helps to absorb calcium, regulate cardiac activity and the activity of the central nervous system. Therefore, it is necessary to constantly replenish its reserves and monitor the daily rate.
The precursor of vitamin D - ergocalciferol (d2) a person receives only with food or dietary supplements. Another source - D3 (cholecalciferol) is formed only under the influence of ultraviolet radiation.
Functions of calciferols
Calciferol from Greek. language means "carrying lime". This substance is a fat-soluble vitamin. It accumulates in deposits of subcutaneous adipose tissue and liver mainly in the summer and is consumed throughout the year as needed.
Calciferol is a steroid hormone commonly found in nature. The active form of vitamin D3 is synthesized by the human kidneys, and helps the body absorb calcium, being responsible for calcium-phosphorus metabolism.
The use of food products containing D2 contributes to the full development and maintenance of bone tissue, blood composition, its coagulability, healthy teeth, nails and hair.
The benefits of vitamin D
Calciferols play an important role in the full functioning of the body:
- They promote the absorption of a sufficient amount of calcium, which protects against the development of osteoporosis, rickets or softening of bone tissue.
- Prevents the development of neoplasms.
- Reduces the risk of depression, schizophrenia and improves mood.
Regular exposure to sunlight or the introduction of foods high in vitamin D into the menu prevents the development of urolithiasis, stimulates the body's defenses, and protects the brain from the formation of proteins that provoke Alzheimer's disease. In old age, the consumption of dietary supplements with D3 along with calcium for several years strengthens bone tissue to the level of a fifty-year-old person.
Timely intake of calciferol during pregnancy and lactation helps prevent the development of rickets in the unborn baby. In this case, women are advised to take 2 tbsp. spoons of fish oil daily from the sixth month of pregnancy. However, exceeding the dosage causes negative consequences, up to premature hardening of the bones in the infant.
Calciferols have the following features:
- With a significant decrease in D3, it will not be possible to quickly replenish it.
- The vitamin is not formed if sunlight enters through glass or clothing.
Relationship with calcium and ultraviolet light
The effectiveness of sunbathing is related to:
- skin color and features (melanin content in it);
- the geographical location of the person;
- time spent in the sun;
- cloudiness;
- environmental situation
Human skin cells contain D4 (dehydrocholesterol). It is from this substance that, under the influence of ultraviolet radiation (spectrum B) with a wavelength of 270 to 315 nm, vitamin D is synthesized. However, at different latitudes and at different times of the day, the intensity of exposure to ultraviolet rays can vary greatly.
It is possible to fully replenish the daily norm of D3 in spring and summer, being in the tropics, the middle or temperate zone. The sun in the conditions of the Arctic and Antarctic will not contribute to the synthesis of this vitamin.
One of the alternative ways to replenish the balance of D3 is a solarium or quartz treatment. The light of UV lamps is devoid of a spectrum harmful to the skin and activates the synthesis of calciferols.
The amount of melanin - the coloring pigment of the skin, depends on the intensity of the action of sunlight. With a high content of pigment in the skin, a natural barrier is created that prevents the passage of ultraviolet rays to the tissues. People with light skin types produce calciferol faster than those with tanned or dark skin. Doctors recommend staying in the sun for at least fifteen minutes a day in the summer, and periodically going to the solarium during the winter.
However, you should not stay in direct sunlight for too long, especially in the summer at lunchtime. Too long a tan for more than one hour leads to dehydration of the skin and its severe aging. Excessive formation of vitamin D leads to an increased concentration of calcium, the pH of the blood changes to alkaline, clotting increases, which leads to the development of many diseases and provoke strokes and heart attacks.
The rate of intake of calciferol
The Ministry of Health of Russia has identified the optimal dosage of vitamin D intake. For adults, it is about 100 IU (2.5 mcg). For young children and pregnant women, the dosage is increased to 400-500 IU (about 10 mcg).
Before you go back for supplements, you should pay attention to your diet, as well as increase your sun exposure. A walk in the summer for half an hour allows the body to produce up to 500-600 IU and replenish calciferol reserves.
Vitamin D deficiency
Insufficient amount of foods in the diet, with calciferol and calcium, rare exposure to sunlight, low physical activity can lead to hypovitaminosis. Vitamin D deficiency is also common in people living in areas with frequent rainfall and in large cities. Vitamin D is present in skin secretions that are removed from the surface of the body through frequent hand washing and excessive personal hygiene.
The lack of calciferol is typical for the elderly, when the process of calcium absorption in the intestines is disturbed. Dark skin color also interferes with the synthesis of the vitamin. Pregnancy, lactation, as well as diseases of the liver and kidneys, which are responsible for the conversion of calciferol into the active form, affect the normal content of the substance.
Vitamin D deficiency manifests itself in the form of:
- caries, tooth decay,
- bone softening, joint pain
- rickets in children
- osteomalacia in adults
- decreased muscle tone,
- diseases of the liver and kidneys,
- dysfunction of the central nervous system,
- general decrease in immunity,
- visual impairment (nearsightedness)
- insomnia,
- depression, memory problems.
Among other things, a lack of vitamin D increases the likelihood of Alzheimer's disease.
Vitamin D is needed for normal absorption of calcium in the intestines. If calciferol is not enough, the content of the microelement in the blood also decreases. In this situation, the body begins to extract calcium from the bones, which leads to the development of acidosis (acidification). This process disrupts the normal functioning of the central nervous system.
Among other things, the lack of calciferol leads to the following problems:
- Decreased tone of muscles and ligaments.
- Weakening of the protective forces and the general tone of the body.
- Violation of cardiac activity.
- Diseases of the kidneys and liver.
- Brittleness of hair and nails.
In order to prevent the development of such complications, it is necessary to monitor the normal intake of vitamin D and sufficient exposure to open sunlight or quartzization, the process of calcium absorption directly depends on these factors.
Excess calciferols
An excess of calciferol can occur due to the following reasons:
- In young children whose parents exceed the required dosage of the drug prescribed by the doctor.
- Quartzization whether prolonged exposure to the sun.
- Excessive consumption of foods high in polyunsaturated fats or dietary supplements.
Among the external manifestations of hypervitaminosis are:
- Muscle cramps.
- Decreased appetite.
- Aggressiveness and irritability.
- Nausea and vomiting.
- Constipation.
- Lethargy and drowsiness, apathy.
- Children may slowly gain weight or even lose weight.
- Paleness of the skin.
- Painful and frequent urination.
- Headaches.
- Sweating.
- Violations of the frequency and rhythm of the heartbeat.
- Strong thirst.
Among the serious disorders in young children, there are delays in mental and physical development, disorders in the functioning of many organs (lungs, spleen, liver, heart muscle). In an adult, it can cause severe poisoning
List and table of foods containing vitamin D
The highest content of vitamin D is found in fish oil. However, not everyone likes this product. You can get enough calciferol from the following foods:
- Fatty varieties of marine fish, especially red ones;
- Cod liver;
- Fish caviar (black, red);
- Dairy products (kefir, milk, cheese, butter). An acidic environment improves the absorption of calcium and vitamin D.
- Mushrooms;
- chicken eggs;
- beef liver;
- A small content of calciferol is noted in many fruits and greens.
Table of vitamin D content in foods
| Product, 100 gr | Vitamin D, mcg |
| halibut liver | 2500 |
| Cod liver | 370-250 |
| Fish fat | 250-230 |
| Atlantic herring | 30 |
| Salmon | 25 |
| Sprats | 20 |
| Keta | 16-17 |
| Mackerel | 15 |
| Mushrooms | 5,1-5,3 |
| Chicken egg | 2-3 |
| Butter | 1,5-2 |
| Cheese | 1 |
| Sour cream 30% | 0,15-0,20 |
| Beef liver | 0,02 |
The greatest assimilation of the vitamin occurs in the presence of calcium, so it is advisable to eat foods containing both components. However, getting the required norm only from food is quite difficult. To do this, you have to eat about one kg of cod, which not everyone can do. In addition to the diet, it is recommended to be in the sun more often and use dietary supplements that a specialist can prescribe.
Medical preparations
In order to compensate for calcium deficiency, in case of hormonal failures or impaired kidney function, doctors may prescribe medicines containing vitamin D. The most common medicines are:
- Oxidevit oil, in the form of capsules or drops.
- Videhol, is available in the form of a solution. Side effects include diarrhea.
- Psorkutan in the form of a cream or ointment. It is prescribed for psoriasis vulgaris of the scalp.
- Aquadetrim, vitamin in aqueous solution. Unlike oil variants, calciferol is more easily absorbed by the body (high bioavailability), quickly absorbed into the blood. The drug is approved for use by women during pregnancy and newborn children.
- Vigantol. Available in the form of drops. Allowed for infants up to a year, including premature ones. Does not contain dyes or artificial additives.
- Ergocalciferol (dragees / alcohol solution, capsules). Used in the treatment or prevention of hypovitaminosis.
Of the combined funds for women's health, the following are distinguished:
- Calcium-D3-nycomed. Available in chewable form, has the addition of orange or mint. Includes calcium carbonate and cholecalciferol.
- Boar. Sold in the form of a spray, which is based on thyrocalcitonin. Helps replenish calcium deficiency.
- Calcium + vitamin C. Of particular importance is for women of age, as well as with a tendency to osteoporosis.
- Calcium Sandoz forte. It is in the form of effervescent tablets. Consists of calcium carbonate and lactogluconate. Increases the absorption of calcium by the intestinal walls.
Contraindications
Before taking vitamin D, you should consult with your doctor, as dietary supplements can cause similar effects, especially during pregnancy and lactation. Exceeding the dosage can lead to violations of the physiological development of the baby and metabolism. Among other things, an excess of vitamin D causes atherosclerosis of the lungs, blood vessels, and heart.
Among the contraindications to the use of calciferol are:
- Individual intolerance to the components.
- Elevated levels of calcium in the blood or urine.
- Hypervitaminosis.
- Renal failure, liver disease.
- active form of tuberculosis.
- Urolithiasis.
- Ulcers of the stomach or duodenum.
- Diseases of the gastrointestinal tract.
Therapist Khalepa Y.V.
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