During the winter months, many people take extra vitamin D because the sun no longer provides us with the vitamin D we need. We in the Nordic countries cannot obtain enough of the vitamin solely from sunlight throughout the entire year and therefore we need to get the vitamin through our diet [1].
There is a lot of advice about how much vitamin D you need to take and how to get the right amount. It is a challenge to find the right answer because opinions are many and they often differ.
Through exposure to sunlight, the body can produce vitamin D itself. This is possible during half of the year up here in the north – from early spring to late autumn. In between, the UV light is too weak to have any effect.
So what is vitamin D and why do we need it?
Vitamin D is an essential nutrient with hormone-like properties. Almost all cells in the human body have specific receptors for the substance. Receptors can be described as small keyholes located on our cells. Like keys, vitamin D is placed into these locks, turned, and then affects various functions in our bodies.
How important is vitamin D?
We have a fundamental need for vitamin D and it is not something we can simply choose to do without. Sufficient levels of vitamin D are necessary, among other things, to maintain normal muscle function, cell division and normal bones. The vitamin is also important for maintaining the normal function of the immune system in both adults and children. These effects of vitamin D and the scientific evidence supporting them have been confirmed by the European Food Safety Authority (EFSA) [2].
What happens if I get too little vitamin D?
Symptoms that may occur with vitamin D deficiency include difficulty concentrating, low mood and muscle weakness [3]. The disease rickets is a direct consequence of prolonged vitamin D deficiency. Severe vitamin D deficiency can also cause seizures [4].
It is often claimed that “you can get what you need through your diet”, but studies show that a large proportion of the population gets too little vitamin D [5,6].
How do we get vitamin D?
We get vitamin D through food and sunlight. Our skin produces vitamin D when we are outdoors during the summer months when the sun's rays are strong enough. During the winter months, the sun is too low here in the Nordic countries for the skin to be able to produce vitamin D, and we therefore need to get the vitamin through our diet. Vitamin D is stored in the body for approximately 3 months [7].
Vitamin D occurs naturally in fish, eggs and meat. A number of other foods are also fortified with vitamin D. Examples of fortified foods include dairy products, margarine and plant-based drinks. In addition, vitamin D supplements are available in all pharmacies, health food stores and grocery stores.
How much vitamin D do you need?
Intake from the sun and from food cannot be compared, but on a sunny summer day in the Nordic countries, between 250–500 micrograms are produced in the skin in just 30 minutes [8]. This is considered fully sufficient. You do not need as much through your diet, but there is disagreement about how much vitamin D you actually need. Opinions differ among different authorities, doctors, researchers and nutrition experts. Representatives of the Swedish Food Agency and some doctors usually say that no supplement is needed at all. Other doctors and researchers believe that an intake of 125 micrograms per day has major positive effects and is risk-free [9].
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What does the Swedish Food Agency say?
The Swedish Food Agency recommends the following intake of vitamin D [10]:
- 10 micrograms per day for children and adults under 75 years of age
- 20 micrograms per day for adults with little or no sun exposure
- 20 micrograms per day for people over 75 years of age
How should I get the right amount of vitamin D?
Let us start from the Swedish Food Agency's recommendations (and disregard the higher recommendations). To reach the recommended intake, you can eat 230 grams of tuna, 300 grams of farmed salmon or 6 eggs every day. Alternatively, you can drink one litre of fortified milk, eat 50 grams of margarine or 400 grams of canned chanterelles. You then need to do this every day. You can of course also take a dietary supplement. It is undoubtedly possible to get vitamin D through your diet, but note that dairy products contain saturated fat and a lot of calories, which in the long term can lead to poor health [11]. If you are over 75 or have little sun exposure, then 12 eggs or 100 grams of margarine applies. If you follow the considerably higher recommendations, the amount will naturally be much greater. Dietary supplements are available in different dosages.
Can you get too much vitamin D?
As with most substances, large amounts can be harmful. Large amounts of vitamin D can lead to excessively high levels of calcium in the blood, calcium deposits in the kidneys and kidney failure. The European Food Safety Authority, EFSA, has set an upper limit for vitamin D of 100 micrograms per day. This comes from identifying 250 micrograms as a level without adverse effects. This level was then divided by 2.5 to establish a safe level with a large margin [12].
Where can I find high-quality dietary supplements?
In your health food store, pharmacy or grocery store you will find well-known and safe products. You can also shop safely online if you purchase from e-commerce sites in Sweden. If you are unsure, you are welcome to contact the industry organisation Svensk Egenvård. We recommend that you choose a supplier that is a member of Svensk Egenvård and follows our regulations.
Svensk Egenvård is an industry organisation that brings together the majority of suppliers and retailers of health food products in Sweden. We are also behind Näringswiki, where you can find more detailed information about nutrients. We disseminate knowledge and information about nutrition and maintain a dialogue between the industry, consumers and authorities.
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1. Nordic Council. Nordic Nutrition Recommendations 2012 – recommendations on nutrition and physical activity. Fifth edition. Copenhagen: Narayana Press; 2012.
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2. [https://www.livsmedelsverket.se/produktion‐handel‐‐kontroll/information‐markning‐och‐pastaenden/narings‐och‐halsopastaenden#H%C3%A4lsop%C3%A5st%C3%A5enden](https://www.livsmedelsverket.se/produktion‐handel‐‐kontroll/information‐markning‐och‐pastaenden/narings‐och‐halsopastaenden#H%C3%A4lsop%C3%A5st%C3%A5enden)
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3. [https://www.internetmedicin.se/behandlingsoversikter/endokrinologi/d‐vitaminbrist/](https://www.internetmedicin.se/behandlingsoversikter/endokrinologi/d‐vitaminbrist/)
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4. [https://www.livsmedelsverket.se/livsmedel‐och‐innehall/naringsamne/vitaminer‐och‐antioxidanter/d‐vitamin](https://www.livsmedelsverket.se/livsmedel‐och‐innehall/naringsamne/vitaminer‐och‐antioxidanter/d‐vitamin)
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5. [https://www.livsmedelsverket.se/matvanor‐halsa‐‐miljo/matvanor‐‐‐undersokningar/riksmaten‐2010‐11‐‐‐vuxna](https://www.livsmedelsverket.se/matvanor‐halsa‐‐miljo/matvanor‐‐‐undersokningar/riksmaten‐2010‐11‐‐‐vuxna)
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6. [https://www.gp.se/nyheter/g%C3%B6teborg/h%C3%A4lften‐av‐g%C3%B6teborgarna‐lider‐av‐d-vitaminbrist‐1.68881](https://www.gp.se/nyheter/g%C3%B6teborg/h%C3%A4lften‐av‐g%C3%B6teborgarna‐lider‐av‐d-vitaminbrist‐1.68881)
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7. Abrahamsson L, Andersson A, Nilsson G. Nutrition for Higher Education – From Basic to Advanced Nutrition. Sixth edition. Stockholm: Liber AB; 2013
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8. Circarma E, Porojnicu AC, Lagunova Z, Dahlback A, Juzeniene A, Moan J. Sun and Sun Beds: Inducers of Vitamin D and Skin Cancer. Anticancer Res. 2009;29(9):3495‐500.
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9. Statement dated 31 July 2015 by Michael E. Holick, Professor of Medicine, Physiology and Biophysics, Director of the Department of Endocrinology, Diabetes and Nutrition, Bone Health Clinic and the Vitamin D, Skin and Bone Research Laboratory at Boston University Medical Center, USA.
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10. Nordic Council. Nordic Nutrition Recommendations 2012 – recommendations on nutrition and physical activity. Fifth edition. Copenhagen: Narayana Press; 2012.
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11. [https://www.livsmedelsverket.se/livsmedel‐och‐innehall/mat‐och‐dryck/mjolk‐och‐mejeriprodukter](https://www.livsmedelsverket.se/livsmedel‐och‐innehall/mat‐och‐dryck/mjolk‐och‐mejeriprodukter)
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12. [https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2012.2813](https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2012.2813
