For about a hundred years, Vitamin D has occupied a place among vital substances for humans discovered and studied by science. Everyone has probably heard about the benefits of the sunshine vitamin, but what exactly is it useful for? This article tells about what vitamin D is, where it is contained, and why its deficiency and overabundance are dangerous.
Vitamin D Forms
Often, all the vitamins of group D are collectively called calciferol, despite the fact that this is the name of a specific vitamin - D3. In medical practice, vitamin D is understood to mean forms D2 and D3; 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 preparation. In published articles, they are most often not shared, even doctors, speaking about vitamin D, mean all its forms. When it comes to a specific vitamin, this is mentioned separately.
According to modern science, vitamin D is presented in six forms:
- D1 is a form that incorporates two steroid derivatives, ergocalciferol and lumisterol. It was first found more than a hundred years ago in the cod liver. In its pure form, vitamin does not occur 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 fatty tissues and consumed as needed.
- D2 , or ergocalciferol, is formed by the action of ultraviolet rays on ergosterol. In nature, it is synthesized by fungi. D2 can be called both vitamin and hormone at the same time - it regulates the level of calcium and phosphorus and at the same time affects the functioning of internal organs with its own receptors. If the body needs calcium or phosphorus, it begins to actively synthesize this vitamin or spend its reserves.
- D3 , or, in other words, cholecalciferol is the most important vitamin of its group. He participates in a huge number of processes at the body 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 bone reserves of the body into the blood.
- D5, or sitocalciferol, in its structure and properties is very similar to vitamin D3, but much less toxic. Due to this, the vitamin is successfully used in medicine - for example, in anti-inflammatory therapy and in the treatment of diabetes.
- D6, aka stigmacalciferol, is considered a low-activity vitamin. 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 dosage: during treatment, drugs are taken in a daily amount of 100-250 micrograms, with prophylaxis - 10-15 micrograms.
When is vitamin D recommended?
- Treatment and prevention of rickets
- Fractures and their poor fusion
- Liver disease
- Increased bone fragility
- Chronic gastritis, pancreatitis
- Low Vitamin D in the body
- Dental tissue disorders
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)
- Gastric and duodenal ulcers
- Active form of pulmonary tuberculosis
- Vitamin D Hypervitaminosis
- Acute renal failure
- Heart defects
- Coronary artery disease
- Chronic kidney disease
With caution, taking vitamin D is necessary when:
- Heart and kidney failure
- During pregnancy and lactation
Even for a healthy person, the dosage of vitamin D is not the same. It all depends on age, weight, the presence of other factors. Normally, the dosage of the vitamin is considered approximately as follows:
- For infants up to 1 year old - 7-10 mcg (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)
Micrograms (mcg) and international units (IU) are used to indicate the dosage of vitamin D. These units are interchangeable. One international unit is 0.025 mcg and one microgram is 40 IU.
The dosages listed are optimal to safely replenish vitamin reserves. 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 does it contain?
Vitamin D is often called a solar vitamin, and for good reason. Almost all of its forms, with the exception of only D2, are synthesized in the epidermis of the skin under the influence 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 the summer, vitamin is enough for the body to function normally, but in winter its production is significantly reduced. A large number of clothes and a short daylight do not allow it to be synthesized in normal quantities.
In addition to synthesis in the human body, vitamin D is found in food, most of it in animal products. So, there is a lot of it in any meat, fish, meat and fish liver, eggs. A high vitamin content is also noted in dairy products.
There is practically no vitamin D in plant foods. In small quantities, it is found in corn oil, potatoes, parsley.
Deficit and oversupply
Vitamin D deficiency is observed in every tenth inhabitant of our planet. A person suffering from hypovitaminosis quickly gets tired, he develops weakness, muscle pain, problems with teeth, eyesight. If you do not pay attention to these symptoms in time, the patient may face more serious diseases - rickets, osteoporosis, arthritis, bone deformities.
Most rickets are prone to small children. 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 vitamin level remains normal, and infants are allowed to give it from the first months of life.
Osteoporosis is another disease associated with hypovitaminosis. It is most common among people of middle age and older and leads to the fact that any, even slight bruising leads to cracks or fractures of bones. It is impossible to completely cure it today, only take vitamin D and painkillers in addition.
Often this list of diseases includes depression and migraine, explaining their development with vitamin deficiency.
Overdose , although less common, still has a place to be. Vitamin D tends to accumulate in the body, and its overabundance can trigger 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 if large doses of preparations containing vitamin D are taken. Long exposure to the sun does not threaten an overabundance - a tan protects human skin from this.
Treatment consists of stopping vitamin intake and a plant-based diet. Being in the sun will also have to be avoided. In some cases, it is necessary to take drugs that remove calcium from the body, or even stationary observation.
A deficiency or excess of vitamin D can be detected using a blood test. For greater reliability, it is recommended that you stop taking vitamin complexes and preparations that may contain it for several days before blood donation.
There are a lot of side effects of vitamin D. They can occur in two situations - in case of misuse or due to individual intolerance. Among these effects, low blood pressure, weakness, irritability, and nausea are noted. If you systematically exceed the daily norm of the vitamin, calcifications can form in the organs.
Vitamin D preparations
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 vitamin, which is an approximate daily intake. The drug is prescribed for the prevention of rickets, it can be taken regardless of the time of meal. It is recommended to breed in a spoon of water.
The drug is available in the form of capsules with an oil solution. Allowed for use by children over 6 years of age and adults - young children can not swallow the whole capsule. 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 a meal, washed down with clean water.
It is an oily solution and is taken similarly to Aquadetrim. It can be used as an injection, an injection is done intramuscularly in the thigh or buttocks.
Calcium D3-Nycomed Forte
Available in the form of citrus or peppermint flavored tablets. One tablet contains the daily intake of vitamin D3 and calcium. It is taken after or with food, intended for children over six years of age and adults.
The drug is made in the form of an oil solution. Suitable for children from birth and adults, prescribed for the prevention of rickets, treatment of osteoporosis.