Vitamin D is an important vitamin for all people, especially for those of us who live in the Nordic countries where the sun's rays are not enough as a source of vitamin D all year round. The sun is our most important source of vitamin D, but something we have to keep in mind is that sunscreen, shade and full-covering clothing reduce or block vitamin D synthesis from the sun. This can be a dilemma because we are very good at applying sunscreen in the summer in Sweden. And of course we should do that BUT then we have to review our vitamin D intake and make sure to give the body it in other ways. People who wear a veil (jihab, niqab or burqa) need to think a little extra about vitamin D as clothing blocks the synthesis of vitamin D.
How can the sun actually give us vitamin D?
Vitamin D is also called the “sunshine vitamin,” and that’s very fitting, as we get the majority of our vitamin D from the sun. When the sun’s UVB rays hit our skin, a chemical reaction occurs with a type of cholesterol found in the skin. The vitamin can then be stored in fatty tissue or converted by the liver and kidneys into an active form that is then used by the body for a variety of important functions.
In just fifteen minutes, the skin can absorb a daily dose of vitamin D from the sun on a nice summer day, IF we don't wear sunscreen. Air pollution and clouds also affect our absorption. We can therefore get a reasonable dose in less time than we have time to turn pink and get sun damage on our skin. After about 30 minutes, the skin is saturated and we no longer convert vitamin D. It is therefore not possible to "overdose" on vitamin D through sunlight.
Does our skin color affect vitamin D synthesis from the sun?
Yes, skin pigmentation affects how quickly we absorb vitamin D from the sun. People with lighter skin absorb UVB rays faster than people with darker skin, and for the same reason, light skin turns red and tans more quickly and easily than darker skin, which is more sun-tolerant. For this reason, it is a bit tricky to recommend a general time frame for how long you need to be in the sun to optimize your vitamin D intake, but between 15–30 minutes is a common recommendation.
Vitamin D is important all year round!
Vitamin D is a fat-soluble vitamin, which means that we can store it in our fatty tissue. So if we are good at sunbathing during the summer months, we fill up our supply, which will then last a couple of months into the fall. But the sun also shines in the fall and winter, don't you think? Yes, it does, but the sun is not at the "right" angle in Sweden during that period, i.e. the UVB rays do not reach us in a way that gives us vitamin D. That is why there is so much talk about the importance of vitamin D during the fall and winter (October-May) in the Nordic countries and many people choose dietary supplements to meet the body's daily needs. Since clothing, clouds and sunscreen make it difficult to absorb vitamin D from the sun, many people choose to take supplements even during the summer. Which is absolutely right, how we choose to get the vitamin is less important, the main thing is that we give our body its daily needs.
How much do we need per day?
The Swedish National Food Agency recommends between 10-20 µg per day depending on age. This is the amount we need to consume EVERY DAY all year round. The Swedish National Food Agency writes: “To get enough vitamin D, the Swedish National Food Agency recommends that certain groups take vitamin D supplements. This applies to all children under 2 years of age and all adults over 75 years of age. This also applies to everyone who does not eat fish or vitamin D-fortified food and everyone who is not exposed to sunlight in the summer. Pregnant and breastfeeding women are covered by the advice if they are included in any of these groups.” Read more about the Swedish National Food Agency’s advice on vitamin D here .
Vitamin D is also found in food – or is it?
Yes, there is vitamin D in food, but unfortunately in limited quantities. You can find vitamin D in fatty fish such as salmon, mackerel and herring, but eggs and meat also contain some vitamin D. Since there is not much natural vitamin D in our food, certain foods are fortified with vitamin D. This applies to certain dairy products (such as yoghurt, fil, milk, etc.), plant-based drinks, margarine and fat mixtures. Groups that are at extra risk of vitamin D deficiency are therefore vegans, vegetarians and people who do not eat fish or who eat fish rarely.