Vitamin D, the sunshine vitamin!
We’ll give you all the information you need about vitamin D: Learn about its functions, sources, formation and how a deficiency can manifest itself. We’ll also share some tips for optimal supply.
1-5 minutes
What our body needs…
…can be found in food. Every food contains a range of nutrients. When consumed in the right quantities, all our body’s physical and mental functions can work as intended. This creates fertile ground for performance, growth and development, and helps preserve our health. Nutrients are vital.
Inadequate consumption will cause deficiencies!
Nutrient deficiency
How to recognise deficiencies
If your body does not get the nutrients it needs, you will develop a nutrient deficiency. The symptoms vary widely depending on the nutrient in question.
Vitamin D: a hot topic
You’ve probably heard of vitamin D before. This vitamin really is in the foreground lately. Especially in winter time, you’ll come across lots of articles in magazines and on the Internet exploring the topic. But what’s actually the truth? Who is more likely to develop a deficiency? Is it even possible to get enough vitamin D? Or do we need to supplement with synthetic alternatives?
We have all the answers for you in this session!
The role of vitamin D
There’s more than one!
When we speak of vitamin D, we imply its various forms – the so-called calciferols. The most important are vitamin D2 (ergocalficerol) and D3 (cholecalciferol). Good to know: vitamin D is fat-soluble! This allows us to stock up on it, for example in our fatty tissue, and to fall back on it in ‘hard’ times. It also means you can overdose if you take in too much synthetic vitamin D, though.
Vitamin D is fat-soluble
Vitamin D for strong bones!
Vitamin D is essential for bone health. It plays a major role in bone mineralisation: for example, it promotes the absorption of calcium and phosphate from food in the body and helps build these into our bones. This makes your bones stronger. Alongside this main function, vitamin D supports muscle development and the immune system.
What is your daily vitamin D requirement?
For all the processes that require vitamin D to run smoothly, you’ll need different amounts depending on your age:
- under 1 year: 10 micrograms
- 1-60 years: 20 micrograms
- over 60 years: 20 micrograms
Occurrence and formation
The sunshine vitamin
Vitamin D is a special vitamin because our body is able to produce it itself when certain conditions are met. But only when sunlight touches the skin. The vitamin D 3 that is formed there gets converted into calcifediol in the liver and then further into calcitriol in the kidneys. Calcitriol is the biologically active form, i.e. the effective form of vitamin D.
The majority (80-90 %) of this vitamin is made in our body. It is difficult to estimate how long you need to spend in the sun for a good dose. The duration can vary a lot. It depends, for example, on the time of year and day, the latitude, your skin type, or your clothing. For example, 10 minutes in the afternoon sun in the summer can be enough when the sun shines straight on your arms and face.
But light alone is not enough
Sunshine that we enjoy through windows is sadly not enough for vitamin D to synthesise. That’s because it needs UV-B rays and these do not make it through the glass. We should therefore be spending time outside in the fresh air.
Which foods contain vitamin D?
We only cover 10-20 % of our vitamin D needs through food – only a small part. It is primarily found in animal derived foods, especially fish. As it is fat-soluble, fatty fish such as salmon, eel, herring, and mackerel are particularly rich in vitamin D. Egg yolk and margarine and some edible mushrooms such as champignons also contain the vitamin.
What should we do in winter?
Since most of the vitamin D is produced when our skin is exposed to sunlight, winter is a real issue due to the days being shorter, the sun not shining for as long or as strongly, and it also being cold and us covering ourselves up with thick clothing. Fortunately, vitamin D is fat-soluble and can be stored in our fatty tissue, for example. That way we can build our stocks in the summer.
Deficiency & high-risk groups
Vitamin D deficiency
Vitamin D deficiency occurs when vitamin D absorption through food, the body’s own production through the skin, or the vitamin D metabolism is impaired over a long period of time. Note, however, that vitamin D levels in the blood may fluctuate seasonally. A lower level does not necessarily mean that you will experience symptoms.
Only a doctor can diagnose a deficiency!
A vitamin D deficiency is something you should take seriously. If there is a shortfall, for example in babies and children, there aren’t enough minerals to build the bones. The bones stay soft and can deform, which leads to rickets. In adults, bones are deprived of minerals, they soften and break more easily! A vitamin D deficiency increases the risk of osteoporosis in old age.
It can also impair muscle strength and heighten proneness to infections.
Who’s at risk?
Vitamin D deficiency is most likely to occur in people who do not spend enough time out in the sun. This includes people who only step outside with their skin fully covered. People with darker skin are more at risk because they can make less vitamin D (or more slowly) due to a higher proportion of the pigment melanin in the skin. Since the ability to produce vitamin D decreases significantly with age, older people tend to develop a deficiency much more frequently than younger people. But the youngest are also at risk: babies get only little vitamin D through their mother’s milk and should not be exposed to direct sunlight.
Certain conditions pose a risk
Some diseases may increase the risk of vitamin D deficiency. These include chronic gastrointestinal conditions, or liver and kidney disorders. Some medicines also interfere with the vitamin D metabolism.
Tanning studio? Nonsense!
Will going to the tanning studio help prevent a deficiency? This is definitely not to be recommended – especially not for children and young people. They increase the risk of skin cancer and are therefore not to be recommended!
Should we take a vitamin D supplement?
Some foods are fortified with vitamin D. But these are not absolutely essential since the focus should always be on the body’s own vitamin D production. Moreover, food supplements are only advisable if a doctor has diagnosed a deficiency. You should be careful not to ‘over supplement’ because too much of fat-soluble vitamins can also cause problems. Infants are an exception here, for whom correctly dosed supplements can be prescribed by the doctor.
Overdose can cause kidney calcification! An oversupply is when vitamin D supplements are taken in excess.
Good vitamin D intake
It is worth watching your vitamin intake. In older age, if this is ensured, bones do not break as easily and muscle strength, balance and brain function are also more protected. The evidence speaks for itself. Whether vitamin D also reduces the risk of certain types of cancer, cardiovascular diseases, and type II diabetes still needs to be studied further.
What you can do:
You should spend plenty of time outdoors – even in winter. Oily fish should definitely be on the menu once or twice a week. These include herring, eel, mackerel or salmon. If you are lucky enough to enjoy some sunshine, vitamin D supplements are not necessary. For those at a high risk such as infants, pregnant and breastfeeding women, or the elderly, supplements can be beneficial – but only if a doctor prescribes the correct dosage.
One final tip: vitamin D is fat-soluble. As such, it is much more easily absorbed if you consume a little fat with your meal. It doesn’t need to be a lot. In fatty fish, the fat already comes filled with vitamin D.