Vitamin D is unique among vitamins. In addition to eating, our body can produce it itself – there is enough sunlight. However, due to our lifestyle and dietary habits, more than 95% of the population of the Czech Republic lacks it.
Vitamin D is one of the fat-soluble vitamins. Vitamin D (calciferol) occurs in two forms – in the form of vitamin D3 and vitamin D2. Vitamin D3 (cholecalciferol) is formed under the action of UV-B radiation directly in the skin. It can also be obtained from animal sources (especially fish oil). Vitamin D2 (ergocalciferol) is produced by plants when exposed to ultraviolet radiation (similar to humans), obtained artificially by irradiating fungi and yeast, its conversion to the active form of vitamin D takes longer than vitamin D3, but it is suitable for vegetarians. and vegans.
Why is vitamin D so important?
Vitamin D in our body affects more than 200 different functions. It plays a vital role in the growth and development of bones in children, as it promotes the proper absorption and use of calcium and phosphorus, which are necessary for hard and strong bones. For the same reason as bones, vitamin D is important for teeth. In addition, vitamin D helps maintain normal muscle function and, as a result, helps reduce the risk of falls, for example, in the elderly, which is clearly associated with unstable posture and muscle weakness. (Falling is a risk factor for bone fractures in men and women aged 60 years and older). In addition, vitamin D is involved in the process of cell division and is important for the proper functioning of the immune system.. The consequence of vitamin D deficiency in early childhood is rickets, which is manifested by deformities of the bones. Vitamin D deficiency is also associated with increased susceptibility to infections. Lack of vitamin D in adulthood contributes to the development of osteoporosis in old age.
Vitamin D supplements are most important in the first year of life for healthy bone development in children . The drug in the form of drops is prescribed by a pediatrician, the dosage for this period of life is, according to the latest recommendations of Czech pediatricians, 400-500 IU per day, which corresponds to 1 drop of the drug. From the second year of life, it is recommended to take vitamin D at least in the winter months.
Why do we lack vitamin D?
The most important source of vitamin for the human body is its production in the skin after exposure to UV-B radiation. Thus, the body receives about 90% of vitamin D, and the remaining 10% comes from food. However, due to our geographical location, where sunlight is not so intense and the sun does not shine at all most of the year, it is difficult to achieve sufficient illumination. In addition, we spend a lot of time indoors, and when we are in the sun, we effectively protect ourselves from the sun’s rays – clothing or sunscreen (which, of course, is correct, because excessive exposure to the sun increases the risk of skin cancer). If we add our diet, which rarely includes fish, then it will not be easy to provide enough of it. For this reason, only about 5% of us have enough vitamin D.! In neighboring countries, some foods are widely enriched with vitamin D, in the Czech Republic it is still very rare, but nutritionists are actively discussing this possibility.
Vitamin D 2
What foods are rich in vitamin D?
Among the foods rich in vitamin D, fish clearly reigns supreme – vitamin D is contained in their fat. The richest source is cod liver oil, as well as salmon, mackerel, tuna or herring, rich in vitamin D. Rainbow trout is recommended from freshwater fish. In addition, although in much smaller amounts, vitamin D is found in the liver, eggs and dairy products. From plant sources, some mushrooms can be named. As we have already mentioned, there are also foods fortified with vitamin D, such as milk, margarine, some yogurts, soy drinks, cereals or baby food. Breast milk contains very little vitamin D.
Is an overdose of vitamin D possible?
It is unlikely that you will overdose vitamin D from your diet or due to ultraviolet radiation. Overdose is possible only through frequent or prolonged use of drugs with a high content of vitamin D . The safe dose for adults is 100 mcg/ day (4000 IU), for children aged 1 to 10 years – 50 mcg / day (2000 IU) and for infants – 25 mcg / day (1000 IU). (EFSA, 2016). If you are taking medications or medications containing vitamin D, always read the information sheet carefully and consult your doctor or pharmacist if you are not sure.