Vitamin D is in short supply in the Nordic countries

Vitamin D is produced in the skin when exposed to sunlight. The vitamin is a fat-soluble nutrient that is absorbed through the skin and transported to the liver and kidneys for further synthesis into the active form vitamin D3 (cholecalciferol). Like adults, children need vitamin D through sunlight, food and/or supplements.

Commonly low levels in the body

During the summer months, sun exposure on the skin can be seen as the main source of vitamin D, but from late autumn until spring there is not really any significant synthesis of vitamin D in the body, as the UV-B radiation is filtered out in the atmosphere when the sun is low. Until just a few years ago, many people assumed that the synthesised amount of vitamin D produced in the body during the summer should cover the need even during the winter months, because vitamin D is fat-soluble and can therefore be stored in the body. However, it is now known that the amount synthesised is often not sufficient and that only some people have produced the amount needed to cover a larger part of the requirement even during the winter months. This puts many people at risk of having too low levels of vitamin D during parts of the year, thereby also increasing their risk of suffering from deficiency symptoms and diseases linked to vitamin D deficiency.

Sunscreen protects - but also blocks vitamin D synthesis

The use of sunscreens has an important role to play in protecting the skin from the harmful effects of the sun's rays. But at the same time, it also blocks the process by which the sun's rays synthesise and create our natural stores of vitamin D. This is particularly evident with children as we often apply extra high SPF to them, which is a good thing, but then we have to bear in mind that it affects the synthesis of vitamin D.