Vitamin D: How to get the sunshine vitamin even in winter

Vitamin D is one of the most discussed vitamins in recent years. Not without reason: It has a special status among vitamins because it acts as a hormone in our body and is mainly formed by UV rays. We only cover about 20 percent through our diet, such as fatty fish and eggs.

Obstacles to the body's own production of vitamin D

A good supply would be so simple, because our body can produce vitamin D itself through the skin. All that is needed for this are the rays of the sun. 80-90 percent of our vitamin D requirement could be covered by this self-production. Could! Because for the vitamin D production to start effectively, some factors must be met:

• The ideal time to fill up your vitamin D stores is spring or summer: From April to September here in this country, the sun is high enough for sufficient UV-B rays to penetrate to us. In the remaining months, the ozone layer surrounding our Earth filters out these rays. October to March we cannot produce vitamin D through the skin.

• This is also the reason why vitamin D production only works from 11 am to 4 pm during the warm season. Early in the morning and later in the evening, the sun is simply too low - no matter how bright and sunny it may be.

• We need to be outdoors. Glass panes filter out UV light for the most part. This means that not enough UV-B rays can reach the skin, causing the production of vitamin D to stop.

• The sky should not be too heavily clouded. Clouds filter out the UV-B rays from sunlight that are important for vitamin D production. UV-A rays can penetrate clouds and the ozone layer more easily, which is why you can still get sunburned even on cloudy days. As a rule of thumb: the bluer the sky, the better the vitamin D production.

• The surface of exposed skin must be large enough. Just exposing the face to the sun is unfortunately not sufficient; at least the arms and ideally also the legs should be exposed in order to absorb sunlight.

• Of course, sun cream is essential in the mountains when the sun is strong, but we don't need sun protection in our everyday lives here in winter. Even a sun protection factor of 10 reduces the production of vitamin D by 95 percent, 15 even by 99 percent. Caution: Many day creams also contain an SPF of 10-15.

• The correct duration of exposure to sunlight varies from skin type to skin type. For fair skin, a duration of 15 minutes is recommended, while for darker skin it may take up to 30 minutes to fill the daily vitamin D stores. However, prolonged exposure beyond what is appropriate for the skin type does not result in more vitamin D, but increases the risk of permanent skin damage.

Sun to swallow: Vitamin D supply through food

A part of the vitamin D supply can be covered through normal nutrition. Unfortunately, the range of foods containing vitamin D is quite limited. For example, 100 g of salmon contain 16 micrograms of vitamin D, significantly less in mushrooms or eggs. However, since hardly anyone eats fatty fish daily, the requirement cannot always be met through food.

"Popular" for a long time was cod liver oil to provide children with vitamin D daily. However, there are also tastier options: smoked eel, sardines, or salmon also provide a certain amount of vitamin D. Organic eggs and mushrooms should also be included in the diet as sources of vitamin D, especially during the dark months.

You can read here which foods should be on your menu to ensure you get enough vitamin D in winter.

As can be seen from the table, however, it is rather difficult to achieve sufficient vitamin D supply through diet. In order to maintain vitamin D levels permanently, foods would have to be consumed daily and in sufficient quantities.

A particularly simple solution to ensure daily intake of vitamin D is LaVita. Just 1-2 tablespoons a day, stirred into a glass of water, cover the daily requirement.

Vitamin D - why it is so important

Vitamin D receptors are found in many parts of our body - for example, in the brain and in the gut - and researchers are discovering more and more interesting connections. Because vitamin D affects numerous areas and mechanisms of the body, a deficiency can have various effects:

• Vitamin D plays an important role in bone health. The vitamin improves calcium absorption from the intestines and promotes its incorporation into our bones. Vitamin D is therefore particularly important in the prevention and treatment of osteoporosis.

• Vitamin D supports our immune system.

• The vitamin is also important for our dental health.

• Because vitamin D also plays a major role in (early) childhood bone development, vitamin D is often supplemented in the form of drops in the first years of life.

Vitamin D: Conversion μg to IU

For vitamin D, the quantity can be expressed either in micrograms (μg) or international units (IU). You can convert between these as follows:

• 1 μg = 40 IU

• 1 I.E. = 0.025 μg

Vitamin D: Who needs how much

• The German Nutrition Society (DGE) recommends that children, adolescents and adults consume 20 µg of vitamin D (800 IU) per day through food.

• However, scientists and doctors still disagree on what constitutes ‘too much’ vitamin D. The European Food Safety Authority (EFSA), for example, has increased the maximum daily intake for adults from 50 µg (2000 IU) to 100 µg (4000 IU).

Risk groups for a vitamin D deficiency

From the points that are necessary for a sufficient, endogenous production of vitamin D, a series of individuals who are particularly at risk of vitamin D deficiency automatically emerges.

Office workers and shift workers

People who spend the majority of their day indoors are particularly at risk of vitamin D deficiency. They often spend crucial daylight hours under thick concrete ceilings and behind thick glass windows. Even the often too short lunch break only provides a few people with the opportunity for a 20-30 minute sunbath. A natural supply of vitamin D through the skin is hardly possible under these circumstances.

Seniors, especially nursing home residents and those in need of care

From the age of 60 onwards, the production of vitamin D through the skin gradually decreases. As people age, their skin becomes thinner and is no longer able to produce as much vitamin D. Therefore, the ability to synthesize vitamin D through the skin is reduced by a whopping 75 percent in a 70-year-old compared to a 20-year-old (with the same sunlight exposure).

To make matters worse, many seniors have to accept physical limitations and sometimes rarely get outside for fresh air. This problem becomes extreme in cases of care dependency and being bedridden.

Children and adolescents

Actually contradictory - why should those who have the most time to spend outside in the sun belong to the risk group? Well, unfortunately, the leisure habits of children and teenagers have not developed in favor of vitamin D production. Instead of spending their time playing outdoors, many prefer to spend their free time on the computer or playing video games. In addition, younger children are already being applied sunscreen in the morning to prevent possible skin damage.

Don't get me wrong - of course it is important that children and adolescents are protected as much as possible from sunburn. However, by doing so, we also eliminate their chance of producing their own vitamin D. A healthy balance is needed here.

People with dark skin color

The darker the skin color, the longer it takes for the skin to produce vitamin D. What in more southern regions provides natural protection against sunburn and resulting skin damage becomes a risk of vitamin D deficiency here. Thus, the necessary daily sun exposure time can increase to 30 minutes or more.

Chronically ill individuals

Depending on the illness, the risk of a vitamin D deficiency can also increase significantly. Since chronically ill people are often physically limited, their time spent outdoors is also often insufficient.

Due to our current way of life, unfortunately many people are no longer able to meet their vitamin D needs on their own. When all these factors come together, it is understandable why there is a high number of people with vitamin D deficiency.

The vitamin D contained in LaVita is natural vitamin D, more specifically vitamin D3 (cholecalciferol), which is obtained from lichens. Vitamin D3 is the form that can be particularly well absorbed by the body.