Vitamin D deficiency in summer

Vitamin D deficiency causes: why you need the sun vitamin all year round

Regardless of whether we are more summer or winter people, we are all fine when the sun is shining. We feel better, our state of mind is better, and we feel energetic. But where does this feeling come from? It is related to the fact that our body is able to produce vitamins with the help of solar radiation, which not only improve our own perception, but are also important and indispensable for the body's health. The sun's vitamin D source is essential. However, since we often have to do without sunlight in some regions of this planet, there are other ways to provide your body with vitamin D intake. In the following it is explained in more detail how high our vitamin D requirement is, which vitamin D deficiency symptoms there are and why UV rays are not only bad for us, but on the contrary can also help us with sleep disorders, for example.

We can produce vitamin D ourselves with the help of UV radiation. And yet many suffer from a vitamin D deficiency, especially in summer when the sun is at its strongest. How do we make vitamin D? How do we recognize a deficiency? We enlighten you!


What is Vitamin D?

Vitamin D is a Nutrient that the body can produce on its own. The body's own synthesis takes place in the skin with the help of the sun (UV light). Vitamin D is not considered a sun vitamin for nothing. We can create it ourselves with the help of UV radiation from the sun.

Provided that we expose our body to the sun for a certain period of time during the day as unprotected as possible. Strictly speaking, vitamin D is not a vitamin, but a prohormone. Even in ancient times, people suffered from rickets or osteomalacia.

Both rickets and osteomalacia are often caused by a severe and chronic vitamin D deficiency. The difference here is in which year of life the disease occurs. While rickets occurs in childhood, doctors call the disease in adults osteomalacia.



The The risk of a slight vitamin D deficiency is particularly high in our latitudes in the winter months, because we spend little time outside and the solar radiation is not intense enough. And in summer? We are actually more often outdoors in the bright sun, lying by the lake or spending the days outside longer.

But that is (in a sense) a mistake. Because: Many people spend most of the summer not in the sun, but in closed rooms, so that the vitamin D values ​​are far too low and require the use of supplements containing the sun vitamin to avoid deficiency.

In addition to the sun, another way to get the sun vitamin is through diet. There are many foods that contain the vitamin, but the vitamin D content is very lowso that it is usually better to absorb the vitamin through the skin.



Vitamin D Deficiency Signs: Why Is The Sun Vitamin So Important?

Vitamin D, more precisely vitamin D3 (cholecalciferol), is not only involved in the absorption of calcium - the sun vitamin can even influence our genetic makeup. It's for that Control of over 2.000 genes. When you consider that every cell in the body has a special receptor to absorb vitamin D, it quickly becomes clear how important the sun vitamin is for your body.

Many areas of our body can benefit from vitamin D. In addition to absorbing calcium (including calcium), the vitamin is also helpful for skin, bone health, teeth, muscles and the immune system. One of the most important tasks is the regulation of the brain messenger substance serotonin.

It also influences the processing of the two neurotransmitters dopamine and norepinephrine, which are also important clocks for our mood. As soon as the vitamin D level is low due to the lack of sunlight, our serotonin level is out of balance. Therefore, if you have a serotonin deficiency in the winter months, you should first think of vitamin D.



What is the difference between Vitamin D2 and Vitamin D3?

In general, vitamin D is always used, but in the literature the vitamin comes as

  • Vitamin D3 (Cholecalciferol)
  • Vitamin D2 (ergocalciferol)

. Vitamin D3 (cholecalciferol) can be produced in the skin with the help of the sun. On the other hand, the vitamin in our diet is also in animal foods, especially in high-fat types of fish, such as

  • Herring 7,80-25,00 micrograms
  • 16,00 micrograms of salmon
  • Chicken egg yolks at 5,60 micrograms
  • 4,00 micrograms of mackerel
  • Total chicken egg with 2,90 micrograms
  • 2,5 - 7,5 micrograms margarine
  • Chanterelles at 2,10 micrograms

contain. All reference values ​​are per 100 grams.

Vitamin D2 (ergocalciferol), on the other hand, occurs exclusively in plant-based foods, however, the body cannot utilize this form as well. So it was difficult for vegans to get enough vitamin D next to the sun for a long time. A deficiency was often very likely, but it has recently become possible to obtain vitamin D3 from mushrooms and lichen species.



How is vitamin D made in the skin by the sun?

Vitamin D will mainly formed by the influence of UVB rays in the skinwhich is why sunlight is so important. Submit in summer 10 to 30 minutes soak in the sun already enough to avoid a vitamin D deficiency.

When you sunbathe, you should Wear clothes that are as short as possible and - depending on skin type, skin color and latitude - a Sunscreens with a low protection factor use. In order to take full advantage of sun exposure and vitamin D synthesis, you should Try to stay outside around lunchtime.

The body's own synthesis of vitamin D goes through several stages before the vitamin is available as bioactive vitamin D3. The precursor of the vitamin is cholesterol, which gets into the skin with the help of lipoproteins. The cholesterol is then converted to 7-dehydrocholesterol. Cholecalciferol is then extracted when the sun shines on the skin.

In the next step, vitamin D3 is hydroxylated in the liver and converted to calcidiol. Calcidiol is the storage form of vitamin D. In the kidneys, it is then converted to calcitriol. Calcitriol has a regulating function in the equilibrium of the calcium-phosphate metabolism.


The more intense the sunbathing and the stronger the sun exposure, the more vitamin D3 the body can produce and the higher the vitamin D level. However, the formation of vitamin D only takes place up to a certain limit, so that an overdose of vitamin D from the sun is impossible.


Symptoms of vitamin D deficiency: when is sunbathing particularly useful?

In order to prevent a deficiency and to be able to produce enough vitamin D with the help of the sun, you have to yourself In our latitudes, expose to direct sunlight for at least half an hour. This is best done in spite of the UV radiation without sunscreen (or with a sunscreen with a low sun protection factor) and in swimwear so that the skin can absorb as much sun and vitamin D as possible.

Between 11 a.m. and 15 p.m., the intensity of the UV radiation from our sun and vitamin D synthesis are strongest. As soon as the intensity of the sunlight decreases in the summer months - and this is already the case from 15 p.m. - vitamin D production also decreases. Often you think you've done enough to get around a vitamin D deficiency, but sometimes your efforts may not be enough due to limiting factors.



How high your vitamin D production ultimately is depends on these factors:

  • Time of day and season
  • Intensity of sunlight
  • Cloud cover
  • Skin type and color
  • degree of latitude
  • Age
  • Fashion
  • Sunscreens
  • SPF factor

In our latitudes, solar radiation is often only strong enough in summer and spring to sufficiently trigger the production of vitamin D. Skin color in particular is another important factor.

Dark skin produces less vitamin D in the sun than light skin. This means that especially dark skin types need more sun in order not to suffer from a deficiency than people with a light skin color. This is due to melanin, which protects the skin from damage from the sun's rays.

Often we sweat easily when sunbathing, but you should still do not shower immediately after exposure to the sun. The body produces vitamin D on the skin, which over time can be absorbed into the bloodstream. If we shower immediately after exposure to the sun, everything is washed off. Therefore, it can also happen that some suffer from a vitamin D deficiency despite exposure to the sun.


Vitamin D foods


Vitamin from sun or food: which is better?

Basically, UVB rays have a much better effect than foods or dietary supplements. Compared: With the help of UVB light, the body can produce up to 20.000 IU of vitamin D.. In our food deliver 100 grams of eel, kippers or herring only a dose of 1.000 to 3.600 IU of vitamin D, which is why the risk of undersupply is particularly high here.

The body can store vitamin D, but they are The body's own reserves are quickly depleted if there is no exposure to the sun for a long period of time. This is especially the case in winter when sunlight is scarce and most of the skin is covered with clothing.

What are the symptoms of a vitamin D deficiency?

Vitamin D is involved in numerous processes, such as

  • the cardiovascular system,
  • the immune system,
  • the brain,
  • the muscles or
  • the nerves,

involved. It is therefore not surprising that a vitamin D deficiency can manifest itself in many different ways.


Permanently low vitamin D levels can cause the following symptoms:

  • concentration problems
  • fatigue
  • headache
  • dizziness
  • mood swings
  • Circulatory and muscle weakness
  • neurological disorders
  • Arrhythmia
  • Susceptibility to infection

occur. Since the Symptoms extremely unspecific and could indicate other nutrient deficits or diseases, affected risk groups should definitely theirs Check vitamin D levels with a blood test to let.



Vitamin D deficiency in summer: what are the causes?

If there is no sunlight, the body's own vitamin D synthesis is severely restricted both in the winter months and in the summer months. That a vitamin D deficiency can also occur in the summer months sounds pretty absurd at first sight.

The fact that we take in too little vitamin D in summer is often due to the lack of sun. Many people stay indoors both at work and during their free time, so they belong to the risk groups for a vitamin D deficiency.


Vitamin D dose summer


The body's own production of vitamin D either hardly takes place or not at all. Many people believe that they can compensate for the lack of sunlight with intense sunbathing on the weekend. However, this is not the case because limits daily vitamin D production is. A deficiency is therefore very likely.

In addition, other factors limit the vitamin D supply. The biggest disruptive factors include:

  • Wearing long clothes
  • Shower immediately after sunbathing
  • The use of sunscreen with a high SPF
  • Age (vitamin D production decreases with age)
  • A severe vitamin D deficiency in winter
  • Skin diseases

As absurd as it sounds: Many people take in far too little vitamin D even in summer, which is why they have to support the supply of vitamin D by consuming foods containing vitamin D or taking specific supplements.


How do I find out if I have a vitamin D deficiency?

If you want to make sure that you do not have a vitamin D deficiency, you can have a blood count done by your doctor or buy the vitamin D test from Cerascreen. Thanks to Cerascreen, you can have your vitamin D values ​​checked from the comfort of your own home. At Cerascreen, however, you not only get a blood test, you also receive a personalized report on how you can optimize your values.

The concentration of calcidiol in the blood is measured here. The measured values ​​are given either in weight or molar concentration units, with 1 ng / ml corresponding to around 2,5 nmol / l.

The National Institute of Health distinguishes between four measuring ranges1:

  • <30 nmol / l or <12 ng / ml: Associated with vitamin D deficiency
  • 30-50 nmol / L or <20 ng / ml: Generally considered inadequate for bone and overall health
  • > 50 nmol / L or> 20 ng / ml: Generally considered adequate for bone and general health
  • > 125 nmol / l or> 50 ng / ml: emerging evidence associates potential adverse effects with such high levels, especially> 150 nmol / l (> 60 ng / ml)


    How high is the vitamin D requirement in summer?

    Amazingly, a higher requirement and an additional supply of vitamin D may also be necessary in summer. The need is either through the diet, for example through the Daily consumption of high-fat types of fish, or covered by taking a special preparation to ensure the formation of vitamin D and protection against a deficiency.

    In order not to have to consume large amounts of fish every day, dietary supplements, for example, are certainly the more pleasant choice. As soon as the supply of vitamin D from the sun is insufficient, an additional intake of vitamin D should be taken to prevent a deficiency. According to the DGE, the daily requirement is between 400 and 1.000 IU.

    Shift workers are even recommended to take a higher intake due to the lack of sun. Here the daily requirement is between 3.000 and 4.000 IU of vitamin stimulate vitamin D production. However, overdosing should not be done on your own. The EFSA states that a daily supplement of 2.000-4.000 IU can be consumed without any health side effects.2



    Which factors can support the absorption of vitamin D?

    Most nutrients rarely work individually, but in combination with other vitamins, minerals or trace elements. These so-called cofactors are not absolutely necessary, but they can support the vitamin D synthesis and compensate for an undersupply.

    The most important cofactors include:

      With a varied diet, which preferably consists of untreated, natural foods, you can ensure an adequate supply of nutrients.

      While vitamin D is often associated with vitamin K, vitamin K is1 contained in leafy green vegetables, eggs and whole grain products, which is why a deficiency is extremely rare. The other types of K2 can be found in fermented foods and liver meat.



      Many people come as a surprise that a vitamin D deficiency can also occur in summer. The risk groups include above all shift workers and people who are mainly and especially at lunchtime in closed rooms and therefore have an undersupply. Vitamin D supplements can therefore not only be necessary in winter, but also in summer to raise the vitamin D level and thus prevent a vitamin D deficiency.



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