The material about the blood test for vitamin D. Everyone knows about the benefits and significance of vitamin D for the body. It is needed for the development of the musculoskeletal system, the strength of bones, teeth and nails, proper metabolism. About where it comes from is also known: exposure to the sun contributes to its synthesis in the body itself, and fatty fish and dairy products replenish their reserves from the outside.
And how do you know if this vitamin is enough, is there an overabundance, and what should you do if the balance is disturbed? The necessary information can be obtained using a special blood test for vitamin D.
What is blood test for vitamin D for?
The study of biological fluids on the content of certain chemical compounds in them provides information about the state of the body. A deficiency or excess of vitamins leads to developmental defects at an early age and the appearance of various diseases at a later one. Blood tests help to identify specific causes and develop a treatment strategy.
What is vitamin D?
Under this name, a group of specific chemical compounds — calciferols (6 varieties) is combined, the most significant of which are two:
- D2 – He is ergocalciferol, which enters the body only with food.
- D3 – cholecalciferol, partially coming from the outside with food, as well as synthesized by skin cells in the sun.
Both compounds are provitamins – substances that need to undergo a certain chemical transformation before they begin to perform their functions. They enter the blood (from the skin in the case of biosynthesis or from the intestine, where they are absorbed from food), then to the liver. In order to assimilate vitamin D, fats must be present in food. In addition, like all fat-soluble compounds, they are able to accumulate in adipose tissue and release as needed.
Activation of cholecalciferol takes place in two stages. First, in the liver cells, a hydroxyl group is attached to it and it turns out 25 OH vitamin D or calcidiol, which in the kidney turns into 1.25 (OH)2D3(1,25-dihydroxy-cholecalciferol) or calcitriol. After all the transformations, the vitamin is ready to fulfill its biological functions.
Role in the body
The main functions of vitamin D include:
- Capturing and ensuring the absorption into the blood of such important trace elements as phosphorus and calcium. The process takes place in the small intestine, where they are released from food during digestion.
- Enhancing the transcription of nucleic acids in cell nuclei, which contributes to the process of cell multiplication and reduces the likelihood of genetic mutations.
- Participation in metabolic processes, thereby increasing immunity and preventing various diseases of the heart, blood vessels and the endocrine system (atherosclerosis, diabetes, autoimmune pathologies are directly related to vitamin deficiency).
- Regulation of the synthesis of important hormones, such as parathyroid. Lack of calciferol leads to increased production of parathyroid hormone, which, in turn, inhibits the formation of bone tissue.
Thus, vitamin D is vital for the normal functioning of the whole organism. It enhances the immune defense, ensures the proper development of the skeleton and the functioning of the muscles, regulates hormonal background, prevents diseases of the cardiovascular and endocrine systems, the musculoskeletal system, skin. In addition, the formation and development of cancer tumors depends on the level of vitamin D.
Indications for analysis
When is it necessary to conduct a blood test for calciferol content? It is usually prescribed by a doctor (you can do an analysis of vitamin D yourself, in a paid laboratory) in the following cases:
- growth retardation and bone deformities in children;
- bone and joint pain, osteoporosis in adults;
- frequent fractures;
- increased levels of parathyroid hormone;
- gastrointestinal diseases (digestive disorders, colitis, chronic pancreatitis, Crohn’s disease);
- systemic lupus erythematosus, especially with extensive lesions of the skin;
- decrease in blood levels of phosphorus and calcium concentrations according to biochemical studies.
The analysis is mandatory carried out before operations on bone tissue, dental implantation, as well as lying patients.
What is the name of the blood test for vitamin D
Laboratory studies on plasma levels of hydroxy-cholecalciferol may be called differently. Designations such as 25-OH vitamin D, 25-hydroxycalciferol, 25-OH vitamin D or 25 (OH) D are used in different laboratories.
The rate of vitamin D in the blood in women and men
In the scientific community for a long time there have been discussions about what kind of calciferol gives the maximum information about its content in the blood and what values to consider the norm. Currently, the best option is to measure the volume of intermediate hydroxy-calciferol – 25 OH vitamin D – in the blood plasma.
The norm for a person, ensuring the health of bones and the organism as a whole, is an indicator not lower than 30 ng per milliliter. And although it was not possible to identify the positive effects of increasing the level, sometimes the optimal range is from 75 to 125 ng per milliliter. For vitamin D, blood levels are the same for men and women. In more detail about the most modern interpretation of values - in the table:
Vitamin status D
Plasma concentration, ng / ml