8 Min
Zuletzt aktualisiert am 17.02.2026
Sunshine vitamin, cholecalciferol, vitamin D3 – vitamin D has many names, and more and more people want to supplement it. What most people don’t know: What is vitamin D actually good for? What does it do in our body? And is the hype really worth it? Let’s take a look together!
Your extra: A self-test to find out whether vitamin D might also be interesting for you!
Your Knowledge To Go: What Is Vitamin D Good For?
Vitamin D is involved in many important processes in the body – from the immune system to bones, muscles and teeth, as well as calcium utilization and cell division.
Vitamin D can be consumed in small amounts through food, but it is mainly produced by the body itself or supplemented via dietary supplements.
You can find out whether supplementation might also be interesting for you in our self-test.
Vitamin D plays a special role for children and older adults aged 60+.
At Vetain, you can buy affordable vitamin D drops.
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Overview: Vitamin D | Effects in the Body
Alright, let’s get straight to the interesting part: What is vitamin D good for? The sunshine vitamin is important for many different areas of our body and is part of many processes.
We’ll look at the most important functions of the vitamin together and briefly explain what that means for your body.
So, what is vitamin D good for?
Immune System
Vitamin D contributes to the normal function of the immune system. And this immune system is essential for all of us in everyday life because it helps defend against pathogens such as bacteria and viruses. An adequate vitamin D supply contributes to this system functioning properly. That’s why many people take vitamin D, especially during the cold season.
That may also clarify why vitamin D3 is important in winter.
What else is vitamin D good for?
Bones, Muscles & Teeth
Bones and muscles are basically the framework of our body. Vitamin D contributes to the maintenance of normal bones and normal muscle function. This is particularly important for older adults aged 60+ – I’ll explain that in more detail later. Well-functioning muscles and bones are often taken for granted in everyday life, and many people don’t realize that vitamin D plays a role here.
In addition, vitamin D contributes to the maintenance of normal teeth – crazy, right? Usually, when it comes to teeth, you only ever hear about fluoride, calcium & co.
Calcium Utilization
Speaking of calcium: Vitamin D also plays a role in calcium metabolism. It contributes to normal absorption and utilization of calcium and thus to a normal calcium level in the blood.
This shows how complex the processes in our body are. So when asking “What is vitamin D3 good for?”, we need to consider not only the direct effects of the vitamin, but also the indirect influences. Because calcium itself contributes to normal muscle function, normal energy metabolism and normal blood clotting.
Cell Health
Vitamin D contributes to the normal function of cell division.
What exactly is cell division? Cell division is an important process in our body in which cells divide (surprise!) and therefore multiply. This helps renew tissues.
When it comes to cells, many people know the term antioxidants. You can find out what that’s all about in the article Foods with antioxidants in winter.
Special Groups
As we’ve already seen, the effects of vitamin D3 are important for all of us. However, there are two groups for whom vitamin D plays a special role. These are children and older adults:
Children: What is vitamin D good for … in children?
Vitamin D contributes to normal growth and normal development of bones in children. No wonder our parents always sent us outside into the sun! ;)
Older adults: What is vitamin D good for … in people aged 60+?
Vitamin D contributes to the reduction of the risk of falling in men and women aged 60 and over (with a daily intake of at least 20 µg vitamin D). Falls are a risk factor for bone fractures, especially at an older age.
How Do You Get Vitamin D?
Okay, enough information about what vitamin D is good for. Now we want to actually absorb the vitamin. How does that work? Unlike other vitamins, vitamin D is not mainly absorbed through food. Instead, our body can produce the vitamin itself when we are exposed to sunlight. Around 80–90% of our vitamin D needs can be produced by the body itself if all conditions are right.
You can read how this works and what conditions apply in our article “Vitamin D in winter”.
In addition, vitamin D can also be consumed in small amounts through food. However, this only covers 10–20% of daily needs – often even less.
Typical vitamin D foods include:
Fatty fish (mackerel, herring, salmon)
Some mushrooms
Liver
Egg yolk
Fortified foods (such as some types of milk or margarine)
We show you more foods with vitamin D here.
As a dietary supplement manufacturer, we know: Since many people (especially vegetarians and vegans) do not eat enough of these foods to absorb sufficient vitamin D and sunlight-based production doesn’t always work perfectly, more and more health-conscious people take vitamin D supplements. These are available, for example, as vitamin D tablets or vitamin D drops. You can learn how to take them correctly in our complete vitamin D intake guide.
Self-test: Is Vitamin D Interesting for You?
We now know what vitamin D is good for and that many people supplement vitamin D. But is the vitamin actually interesting for you?
Do you live in a country where the sun doesn’t shine every day? In Germany, for example, the sun is a rather rare guest in winter.
Do you spend less than 15–20 minutes in the midday sun on most days (without sunscreen)?
Are you mainly indoors during the day (office, university, …)?
Do you eat vegetarian or vegan?
Do you eat typical vitamin D foods rather rarely?
Is it currently autumn or winter?
Do you have a medically diagnosed vitamin D deficiency?
Do you have dark skin?
Are you over 60 years old?
Are you currently taking NO supplement yet? (Yes = you are not taking a supplement yet, No = you are already taking one)
Count your “Yes” answers and click on your result to get your evaluation:
0–3× Yes
At the moment, only a few of the points mentioned apply to you.
Maybe vitamin D isn’t a big topic for you right now – but it can’t hurt to understand the basic functions of the vitamin in the body.
4–7× Yes
Some of the points match your everyday life.
That can be a good reason to take a closer look at vitamin D.
8–10× Yes
Many of the factors mentioned apply to you.
Vitamin D seems to be an interesting nutrition topic for you. If you want, you can now dive deeper into the topic and learn more about vitamin D in everyday life.
Of course, this test does not replace a blood test carried out by a doctor. Still, it can give you an initial indication of the role vitamin D may play in your life. If you have any questions, feel free to contact your doctor.
If you’ve become a vitamin D fan too, you can buy your vitamin D drops here directly or find out whether vitamin D tablets or drops suit you better:
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Conclusion: What Is Vitamin D Good For?
So – do you now know what vitamin D is good for? If you need even more information, feel free to check out our product page – there you’ll find more facts & explanations on the effects of vitamin D.
By the way: We receive many messages every day like “Is vitamin D good for skin?”, “Is vitamin D good for hair?”, or “Is vitamin D good for mental health?”. Please note that in this blog we are only allowed to make statements about effects that have been approved by the EFSA as a “health claim”. For these questions, feel free to check different forums or read some studies yourself – there are really interesting findings in these areas. And if you then decide to supplement vitamin D, we’d be happy if you come back to us (either to this article “What is vitamin D good for?” or to our supplement range).
Do you have questions? Then feel free to send me an email – I look forward to hearing from you! :)
The information shared in this article does not replace individual medical or nutritional advice.
Literatur & Quellen
BfR (Bundesinstitut für Risikobewertung) (2023). Nahrungsergänzungsmittel mit Vitamin D – sinnvoll oder überflüssig?
BfR (Bundesinstitut für Risikobewertung) (2014). Ausgewählte Fragen und Antworten zu Vitamin D.
DGE (o.J.). Vitamin D. https://www.dge.de/wissenschaft/referenzwerte/vitamin-d/
Ehlers, A.; Frimmer, V.; Linseisen, J. & Scholl, J. (2025). Wer sollte Vitamin D einnehmen? In: Deutsches Ärzteblatt, 122(6).
Mensink, G.B.M. & Rabenberg, M. (2016). Vitamin-D-Status in Deutschland. In: Journal of Health Monitoring, 1(2).
