No life without vitamin D3
Vitamin D3 is a fat-soluble vitamin which is essential for our body. Only a very small part of the daily vitamin D3 requirement is absorbed through food (approx. 5-20%), the rest of the requirement must be covered by our body through the sun's exposure of the skin. Compared to young people, older people have the disadvantage that only about 1/3 of the vitamin D3 can be synthesized through the skin. This is due to the fact that the enzymes required for this are reduced with age.
Vitamin D deficiency in Switzerland
The Federal Office of Public Health has commissioned a study to analyse vitamin D3 deficiency in the population. According to data on 25-hydroxyvitamin D (25[OH]D) serum concentrations in the Swiss population and in neighbouring countries, it can be assumed that about 50% of the population has a 25(OH)D concentration of less than 50 nmol/l and less than 30% of the population has a 25(OH)D concentration above 75 nmol/l. It is clearly recommended to remedy this deficiency with preparations from the pharmacy.
Effect of vitamin D
Vitamin D is also known as cholecalciferol in the technical jargon and plays an essential role in the regulation of the calcium level in the blood and in bone formation. A deficiency of vitamin D leads to bone loss, especially in older people, and thus to fractures.
Vitamin D3 has many other functions in addition to the task of absorbing and utilising calcium and thus maintaining normal bone mass. Muscle function and the immune system also need vitamin D3 in sufficient quantities. Research is also currently underway into the connection between depression and a lack of vitamin D3.
According to a British study, an undersupply of vitamin D is also often associated with a pathological decline in brain performance in old age. In addition, older people with vitamin D deficiency are more likely to suffer from cognitive impairment, anxiety and depression.
Difference in vitamin D formation summer versus winter
During the winter months the proportion of UV-B rays is low, so it is particularly during the winter months that a large part of the population suffers from a vitamin D3 deficiency. We draw our reserves from the fatty tissue, since vitamin D3 is known to be a fat-soluble vitamin. In the summer months, however, even a short exposure to the sun is sufficient to supply us with sufficient vitamin D3. At the same time, the skin forms the summer tan via melanin to protect against radiation. The tan not only protects us from sunburn, but also from an overdose of vitamin D, because melanin is able to absorb UV-B radiation in the wavelengths of 290-320 nm and thus no further vitamin D3 is produced.
Formation by sunlight
The UV-B component in sunlight is responsible for vitamin D3 formation through sun exposure. Various factors influence the light intensity and the final vitamin D3 formation in the skin, such as the position of the sun, the height above sea level, the composition of the earth's surface, cloudiness, smog or ozone. Window glass absorbs almost all UVB components in sunlight and sunscreen impedes vitamin D3 production by more than 97% already at SPF 8. A visit to a solarium is usually not beneficial, as the skin is usually irradiated with UV-A light rather than UV-B light.
Vitamin D3 in food
Some high-fat foods contribute to the vitamin D supply, such as mackerel, salmon, tuna, redfish, liver, egg yolk, butter, cream, as well as mushrooms, porcini mushrooms and chanterelles. However, only up to 20 percent of the daily requirements can be covered by food.
Vitamin D3 for babies and toddlers
Every baby in Switzerland should be provided with additional vitamin D for the first few months of his or her life. Vitamin D is responsible for the absorption of calcium into your baby's bones and teeth. Since babies are not exposed to the sun in the first few months, their skin is not able to produce its own vitamin D. The Federal Office of Public Health has issued recommendations for vitamin D supplementation in 2012.
Vitamin D3 products for adults
Vitamin K in food supplements
Many dietary supplements combine vitamin D, with vitamin K or calcium to achieve an even better and stronger effect for the preservation of our bones.
Our immune system
We explain how the immune system works, how it can get out of balance, how to support it both short-term and long-term and how to avoid bad influences.
What is the difference between UVA and UVB rays? What must be taken into account for children's skin? And how can I prepare the skin for the sun?