Vitamin D deficiency

The Karolinska Institute in Sweden has established current levels of vitamin D as follows:

< 25 nmol/L = Shortage
25-49 nmol/L = Possible shortage
50-250 nmol/L = Normal
75 – 125 nmol/L = Possibly optimal
> 250 nmol/L = Possibly toxic

Vitamin D, which is actually a hormone, is important for our bones and teeth as it helps to regulate the calcium balance both in our bones and to maintain normal calcium levels in the blood. The vitamin also contributes to the normal function of the immune system and plays an important role in many processes in our body. Are you deficient? Test at home and get answers in minutes.

Vitamin D deficiency symptoms

Vitamin D deficiency in adults leads to osteomalacia, a softening of the bones. One of the main causes of osteoporosis is vitamin D deficiency. The vitamin is needed to absorb calcium in the gut, and when blood calcium levels are low, bones begin to leach out to raise calcium levels.

Research findings also suggest that vitamin D deficiency can contribute to many other diseases. For example, links have been found to various infectious diseases, diabetes, MS and various cancers. The results do not show that deficiency is a cause of these diseases, but rather an important contributing factor.

Vitamin D deficiency in children can cause rickets, the so-called English disease, which is a soft and deformed skeleton.

There are certain groups that are at risk of not getting enough vitamin D and these groups may therefore need supplements. Before starting supplements, it is important to test your levels with a vitamin D test as large amounts of the vitamin are toxic. Excessive intake can also cause nausea, increase the risk of fractures, lead to high levels of calcium in the blood and calcium storage in the kidneys which can lead to kidney failure. It is not possible to get too high levels of the vitamin through food intake alone; this applies if you take supplements.

According to a report from the Swedish National Food Agency in 2018 (in swedish), studies show that a relatively large proportion of the population does not get enough vitamin D according to recommendations. Another study from 2018 shows that one in ten young people may have a vitamin D deficiency. Based on these results, the Swedish National Food Agency has chosen to expand who is included in risk groups for deficiency and has chosen to enrich more and more foods with the vitamin.

Symptoms of vitamin D deficiency include extreme fatigue, poor appetite, pain in the hands, arms, feet and back, blood clots and obesity. A severe deficiency of the vitamin can cause seizures. However, severe deficiency is very rare in Sweden. Mild deficiency is quite common, in fact, deficiency of the vitamin is considered underdiagnosed as the symptoms are often diffuse or even non-existent, sometimes vitamin D deficiency can be confused with other conditions. Therefore, deficiency is often not detected during regular visits to the health center. Even mild deficiency can cause significant symptoms, especially if the deficiency has been long-standing.


Depression may in some cases be linked to low levels of vitamin D.


A low level of the vitamin can also make you feel more tired than usual and less energetic.

Low mood and irritability

If you often feel in a bad mood or extra irritable and angry, the vitamin may have affected serotonin levels in the body. Serotonin is our feel-good hormone.

High blood pressure

Vitamin D helps keep blood pressure at healthy levels. High blood pressure can be a sign of low levels.

Weak muscles and reduced stamina

Vitamin D deficiency can affect muscle performance and a symptom of deficiency can include muscle weakness or reduced stamina.

The symptoms may also be due to other causes

Keep in mind that several of these symptoms can be due to completely different causes and therefore it is important to test for vitamin D deficiency before taking any extra supplements for this. It can also take a long time to develop any symptoms so the most important advice is to eat a varied diet.

Who is at risk and what is the daily requirement for vitamin D?

The average daily requirement is 7.5 micrograms per day. Dietary intake of the daily requirement varies for different ages and depending on how much a person exposes their skin to the sun. The recommendations for northerners were recently raised because studies have shown that we need more of this vitamin than researchers previously thought. New recommendations from the Swedish Food Agency for adults are 10 micrograms per day.

The daily requirement may also be difficult to achieve for special risk groups such as vegetarians, vegans, allergy sufferers and people who do not eat fish and foods enriched with the vitamin. Even people who avoid sun exposure may have difficulties in reaching the daily requirement. For these groups, it may be appropriate to supplement the vitamin mainly during the winter months for those who spend time in the sun during the summer.

How do we get vitamin D?

The main source of vitamin D is sunlight during the summer months. The vitamin is formed from the cholesterol in our skin when the skin is exposed to direct sunlight. To meet a daily intake of 5-10 micrograms, we need to be in the sun with direct sunlight on our bodies for up to 15 minutes 2-3 times a week. The vitamin is best absorbed by exposure to the face and the inside of the forearms in particular. The Swedish winter sun is not strong enough for the skin to produce vitamin D and the body must therefore use what has been stored in the body during the summer. If enough has been stored in the body during the summer, it can cover part of the need even during the winter months. However, this is quite unusual for those of us living in Sweden.

Vitamin D is also found in our food, but often in limited amounts and it can be difficult to get enough through the diet alone. This is why the sun in the summer is so important for us. The largest amount of vitamin D is found in fish, especially oily fish such as salmon, mackerel, herring and tilapia. Other important sources are eggs - the yolk itself, meat, some mushrooms and foods fortified with vitamin D. This can be found, for example, in dairy products, margarine and blended fats.

There are two forms of vitamin D: vitamin D3, which is produced in our skin and found in fish, meat and eggs, and vitamin D2, which is found in mushrooms and fortified foods.

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