It is generally accepted that almost all inhabitants of the Northern Hemisphere are at risk of vitamin D deficiency . Is everything so simple? Vitamin D, which is more of a hormone, is called two fat-soluble substances that are similar in chemical structure and action: ergocalciferol ( vitamin D2 ) and colecalciferol ( vitamin D3 ).

Natural sources of ergocalciferol and cholecalciferol .

Vitamin D2 (ergocalciferol) is found in small amounts in food: fish oil, liver, caviar, egg yolk, butter, milk, cheese, and some plants.

Vitamin D3 is produced in human skin cells when exposed to ultraviolet rays from sunlight. The amount of synthesized vitamin D3 ( cholecalciferol ) depends on:

• wavelengths of ultraviolet radiation (the middle spectrum is most effective);
• pigmentation of the skin (in people with dark skin color, less Vit. D is synthesized);
• age (with age, the synthesis of cholecalciferol decreases);
• environmental conditions (industrial pollution and dust block ultraviolet rays and, accordingly, interfere with the synthesis of colecalciferol ).

The biological role of vitamin D.

Vitamin D is involved in calcium metabolism and sootvetstveno responsible for bone health. Thus, severe and / or prolonged vitamin D deficiency can provoke bone mineralization disorders and diseases such as rickets in young children and osteomalacia (defects in bone matrix mineralization) in adults. Vitamin D is the main vehicle for calcium in our body. Without it, calcium, which is responsible for the correct formation of teeth, bones and ensures the strength of the skeleton, simply cannot be absorbed. For adults, the risk of developing osteoporosis is increased. The danger is that any bruise and minor injury will lead to cracks or fractures of the bones.

In addition to bone problems, the lack of this vitamin is associated with the development of a number of cancer and cardiovascular diseases, immune disorders and allergic diseases in children, as well as depression, migraines and diabetes.

Rules for taking vitamin D supplements and preparations.

It is the only vitamin that the body can produce on its own, but only with a sufficient amount of ultraviolet radiation. Since the sun is very rare in winter, without additional intake of vitamins, there really is a risk of developing rickets in babies and problems associated with its deficiency in adults.

Poor diet and lack of sun exposure are independent risk factors for the development of vitamin D deficiency. However, if you decide to use vitamin D supplements, then they should only be taken in a prophylactic dose. But nevertheless, before taking such supplements, it is recommended to first make an analysis, according to the results of which it is possible to determine the dose of a corrective drug (prophylactic or therapeutic).

According to European medical standards, recommendations for vitamin D supplementation should be based primarily on serum 25 (OH) D concentrations.

Determination of vitamin D deficiency can only be done with a blood test, otherwise the diagnosis cannot be made. Since deficiency symptoms are not specific – weakness, fatigue, muscle pain, tooth decay, decreased vision and lack of appetite. You can avoid vitamin deficiency by starting taking vitamin D in advance, but only after consulting a doctor.

The fact is that when determining the dosage, the region of residence, the characteristics of the organism, the season and concomitant diseases are taken into account. Vitamin D can accumulate in the body, so there is a risk of overdose when taking high doses. Headache, weakness, nausea, muscle and joint pain, fever and even hypertension are all symptoms of an excess of vitamin D in the body. A consequence of an overdose of vitamin D can be the formation of atherosclerotic plaques on the walls of blood vessels. This is facilitated by an increased concentration of calcium in the blood and a lack of magnesium. Remember, not everyone can take vitamin D supplements. Contraindications are high calcium levels in the blood, stomach and duodenal ulcers, acute renal or hepatic failure, chronic kidney and liver diseases, active tuberculosis, as well as some heart diseases (congenital malformation, ischemic disease, myocarditis, myocardiopathy ).