Vitamin D, its significance, deficiencies and sources in nutrition

From a chemical standpoint, Vitamin D (also known as cholecalciferol or ergocalcyferol) is a lipid steroid chemical substance produced from cholesterol. It exists in two distinct forms in the side chain. It was discovered and isolated in 1918. Together with vitamins A, K, and E, it is a fat-soluble vitamin. A distinguishing feature of vitamin D is that adult individuals (excluding pregnant women) can synthesize it in the skin from the provitamins present there. The production of this vitamin is influenced by factors such as season, cloud cover, air pollution, application of sunscreen, and skin aging. Adequate exposure of the skin to sunlight is necessary for the proper synthesis of vitamin D and the development of its active form. Interestingly, as little as 30 minutes in the sun is sufficient for our skin to carry out the vitamin D synthesis process, which is a unique characteristic not found in any other vitamin.

The most significant role of vitamin D in the body is its impact on the skeletal system. It ensures our bones are properly mineralized, which lessens their vulnerability to injury. Vitamin D also stimulates the immune system, preventing us from developing cavities. When our teeth are under attack by bacteria, vitamin D stimulates the production of defense proteins that shield them from decay. Cholecalciferol also affects the state and correct functioning of our neurons and muscles. Thanks to its characteristic chain structure, vitamin D has an antibacterial effect. Providing it in adequate amounts is crucial for those trying to start a family, as it increases spermatogenesis in men and promotes fertility in women.

Situations in which there is an insufficient amount of vitamin D are quite common. The main reason for this insufficiency is an inadequate amount of this substance in the daily diet. The use of alternative diets such as vegetarianism also increases the risk of insufficiency. Another situation that can lead to an insufficient amount of vitamin D is liver-bowel disorders, which limit the absorption of this substance from the digestive tract. Another reason for an insufficient amount of vitamin D is aging of the body, where physiological life processes are reduced and disrupted. In old age, there may be an insufficient amount of vitamin D, as there are fewer opportunities for its absorption from food and less exposure to sunlight. As a result, an insufficient amount of vitamin D leads to disturbances in the metabolism of calcium and phosphorus in the blood plasma, which in turn leads to harmful changes in the bones. In children, an insufficient amount of vitamin D can lead to rickets, while in adults, this insufficiency leads to osteomalacia.

Overall, the body's requirement for vitamin D varies greatly and depends on various factors such as: gender, age, physiological condition and health status. For an adult, this value is usually around 10 micrograms, which is a small amount, but it is still difficult to ensure a balanced diet with this component, without eating fish and fish products every day. It is worth mentioning that a healthy person who spends a lot of time in the sun can meet their needs thanks to endogenous synthesis with protein D up to 90 percent. Unfortunately, vitamin D is present in only a limited number of food groups. The knowledge about cholecalciferol sources in the diet of most of the population is limited to mentioning dairy products and fish. Seafood such as eel, herring, sardine, mackerel, halibut, sprat, and many others are particularly rich in this component. Fish are also valuable to eat due to the presence of beneficial omega fatty acids. The next product group is milk, dairy products and eggs, which contain less of this component compared to fish. However, due to their general use, they form a fairly good source.