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-coverage clothing reduce or block vitamin D synthesis from the sun. This can be a dilemma because we are very good at smearing ourselves with 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 burka) need to think a little extra about vitamin D, as clothes block the synthesis of vitamin D.
How can the sun actually give us vitamin D?
Vitamin D is also called the "sunshine vitamin" and it is very appropriate as we get the majority of all vitamin D from the sun. When the sun's UVB rays reach our skin, a chemical reaction takes place together with a type of cholesterol found in the skin. The vitamin can then be stored in the fat tissue or converted via the liver and kidneys into an active form which is then used by the body for a number of different important functions.
In just a quarter of an hour, the skin can absorb a daily dose of vitamin D from the sun on a fine summer day, IF we are not wearing sunscreen. Air pollution and clouds also affect our absorption. We can therefore take in a suitable dose in a shorter time than we have time to turn pink and get sun damage on the skin. After about 30 minutes, the skin is saturated and we do not convert more vitamin D. It is therefore not possible to "overdose" vitamin D via 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 the UVB rays faster than people with darker skin and it is for the same reason that light skin gets red and tanned faster and more easily than darker skin that can withstand the sun better. For this reason, it is a bit unwise to recommend a general time span for how long you need 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 we can store it in our fat tissue. So if we are good at sunbathing in the summer months, we replenish our supply, which will then last a couple of months into the autumn. But the sun also shines in autumn and winter, don't you think? Yes, it does, but during that period the sun is not at the "correct" angle in Sweden, i.e. the UBV rays do not reach us in a way that gives us vitamin D. This is why there is so much talk about the importance of vitamin D during autumn and winter (October-May) in the Nordics, and many choose dietary supplements to meet the body's daily needs. Because clothes, clouds and sunscreen make it difficult to get vitamin D from the sun, many 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 the body its daily needs.
How much do we need per day?
The Swedish Food Agency recommends between 10-20 µg per day depending on age. This is the amount we need to get EVERY DAY all year round. This is how the Swedish Food Agency writes: "In order to get enough vitamin D, the Swedish Food Agency recommends that certain groups take dietary supplements with vitamin D. This applies to all children under the age of 2 and all adults over the age of 75. This also applies to anyone who does not eat fish or vitamin D-enriched food and anyone who is not exposed to sunlight in the summer. Pregnant and breastfeeding women are covered by the advice if they are part of one of these groups.” Read more about Livsmedel's advice on vitamin D here .
Vitamin D is also found in food - right?
Yes, there is vitamin D in food too, but unfortunately in limited quantities. You find vitamin D in fatty fish such as salmon, mackerel and herring but also eggs and meat contain little vitamin D. Since there is not much natural vitamin D in our food, certain foods are fortified with vitamin D. This applies to certain milk products (such as yogurt, cheese, milk etc.), plant-based drinks, margarine and cooking fat mixtures. Groups at extra risk of vitamin D deficiency are therefore vegans, vegetarians and people who do not eat fish or who rarely eat fish.
