Why your body needs vitamin D3 – and why so many people have too little of it
Vitamin D3 – also known as the sunshine vitamin – is one of the most important nutrients for your entire body. Hardly any other vitamin is so closely linked to your lifestyle, your environment, and the seasons. And although your body can generally produce vitamin D3 itself , studies show that 30–60% of people in Germany and Austria have low vitamin D levels, especially in autumn and winter.
Why is that?
What role does vitamin D3 play in your entire body?
And what can you do to keep an eye on your long-term healthcare needs?
This detailed article contains all the important information.
What makes vitamin D3 so special
Vitamin D3 is not an ordinary vitamin. Your body can produce it itself with the help of sunlight – more precisely, through UVB radiation that reaches your skin. This ability makes vitamin D3 unique, because most other vitamins must be obtained entirely through food. With vitamin D3, however, your body is actively involved: it produces the vitamin in the skin, then converts it in the liver, and finally activates it in the kidneys. Only then can vitamin D3 fulfill its diverse functions in the body.
But this very characteristic presents a challenge: the conditions your body needs for vitamin D production are often not present in our modern daily lives. We spend more and more time indoors, protect our skin with clothing and sunscreen for good reason, and live in a climate where the sun is too weak for many months of the year to reliably stimulate vitamin D synthesis. Individual factors such as age, skin type, and geographical location also play a role. The interplay of all these influences means that the body's own production of vitamin D3 is often significantly lower than your body actually needs.
Why our modern lifestyle makes vitamin D production more difficult
Our daily lives take place predominantly indoors: in the office, working from home, in the car, in shops, or simply at home. At the same time, winters in Central Europe are long, cold, and lack sunshine. While clothing and sunscreen reliably protect your skin, they also prevent sufficient UVB radiation from reaching it.
The result: Vitamin D3 is essential – and yet many people produce far too little of it. Studies show that 30–60% of people in German-speaking countries do not reach the desired vitamin D status, especially in autumn and winter. There are many reasons for this:
1. Too little sun in winter
From October to March, UVB radiation is insufficient in our latitudes to effectively produce vitamin D.
2. Everyday life takes place indoors.
Windows block UVB radiation almost completely.
3. Clothing and sunscreen reduce vitamin D production.
Both protect your skin – but also prevent the body's own synthesis.
4. Skin type and age play a role
Darker skin types need more sun, older people produce less vitamin D.
5. Nutrition provides only small amounts
Few foods contain relevant amounts of vitamin D3.
Why Vitamin D3 is so important for your body
Vitamin D contributes to the normal function of the immune system.
Your immune system works constantly – whether you're sleeping, working, or taking a walk. It detects countless external influences every day and decides in a flash how to react. Vitamin D plays a crucial role in this complex interplay by supporting various immune cells in their normal function. These include, for example, T cells and other defense cells, which can only become truly active when the conditions in the body are right. A well-nourished immune system doesn't mean you'll be "invincible" – but it does mean that your body's own defense mechanisms can work as they should. Vitamin D thus helps your immune system to react reliably and effectively day after day.
Vitamin D contributes to normal blood calcium levels.
A stable calcium level in the blood is essential for numerous everyday processes – including the excitability of muscles and nerves. Your body is very careful to ensure that the calcium level is neither too high nor too low. Vitamin D helps to support this balance. It influences how much calcium is absorbed from food, how much circulates in the body, and how much is released from stores. This finely tuned system is a key reason why vitamin D3 is so valuable: It helps to keep internal processes stable and ensures that calcium is available where it is needed.
Vitamin D contributes to the maintenance of normal bones and teeth.
Your bones are living structures that are constantly building up and breaking down, even if you don't notice it. Vitamin D3 plays a central role here because it supports normal calcium absorption and thus contributes significantly to building and maintaining your bones. Without sufficient vitamin D, your body struggles to incorporate calcium into bone structures. The same applies to teeth: strong tooth enamel depends on a functioning calcium metabolism in the long term. Understanding how closely vitamin D3 is linked to these processes quickly makes it clear why a good supply throughout the year is so important – not just for the moment, but for your entire lifespan.
Vitamin D contributes to the maintenance of normal muscle function.
Your muscles perform impressive work every day, even during everyday movements. From getting up and carrying shopping bags to physical exertion, much depends on how well your neuromuscular system functions. Vitamin D plays a supportive role within this system, participating in processes necessary for normal muscle contraction and function. This can become particularly relevant as we age, since the body requires more support to maintain muscle function. A good vitamin D level helps ensure that your muscles can function reliably in everyday life.
Vitamin D plays a role in cell division.
Your body is a true masterpiece of regeneration: Every day, millions of new cells are formed while old cells are replaced. Whether it's skin, blood, mucous membranes, or numerous other tissues, cell division processes are constantly taking place everywhere. Vitamin D supports these normal processes by playing a role in cell division. This doesn't mean that it creates "more cells" or works miracles, but rather that it helps your body efficiently carry out its natural renewal processes. Precisely because cell division is a foundation of all regeneration, this effect is often underestimated, yet it is one of the most important biological functions that vitamin D supports.
Why nutrition alone is often not enough
Even though a few foods like salmon, herring, mackerel, eggs, or certain fortified products contain vitamin D, the amounts available in our diets are often very low in reality. To get enough vitamin D from food alone, you would have to eat unrealistically large quantities every day—amounts that would be neither practical nor balanced in everyday life. Even people who regularly consume fish often don't come close to reaching the levels their bodies ideally need.
Another point: Many people eat too little fish, consciously avoid animal products, or choose diets that are low in vitamin D-rich foods. This makes it even more difficult to meet the body's needs solely through diet. At the same time, vitamin D is fat-soluble, meaning that its absorption in the body depends heavily on the composition of a meal and whether it contains enough healthy fats.
All of this shows that while our diet does play a part, it can usually only make a small contribution to our daily vitamin D intake. That's precisely why it makes sense for many people to consciously supplement their vitamin D intake, especially during times when sunlight is scarce and the body relies on alternative sources.
NN Vitamin D3 2500 IU – high-quality support in convenient drop form
When the sun takes a break and your body's own vitamin D production practically stops, NN Vitamin D3 2500 IU is a simple way to support your body. Each drop provides you with 2500 IU of vitamin D3 – highly bioavailable, vegan, and pleasantly easy to dose.
Especially during the darker months or if you get little sunlight, it can be beneficial to keep a close eye on your vitamin D levels. These drops can be easily integrated into your routine and help you feel reliably supplied, without unnecessary additives or complicated dosage methods.
- 2500 IU vitamin D3 per drop
- Droplet shape for maximum bioavailability
- simple, flexible dosage
- ideal for autumn, winter and periods of life with little sunshine
Why Vitamin K2 (MK7) can be a valuable supplement
Vitamin D3 helps your body absorb calcium, but vitamin K2 plays a crucial role in ensuring that calcium is properly utilized by the body. The MK7 form (menaquinone-7) is particularly important because it is highly bioavailable and remains active in the body for a longer period.
Many people consciously choose to use vitamin D3 and vitamin K2 together to holistically support calcium metabolism processes – always within the framework of a healthy lifestyle.
Vitamin D3 + K2 – the powerful duo for your everyday life
NN Vitamin D3 + K2 combines 2,500 IU of vitamin D3 per drop with high-quality vitamin K2 in the MK7 form, a particularly bioavailable variant that remains active in the body for longer. The drops offer a perfectly balanced combination for anyone who wants to use both vitamins together.
This wording will help you to optimally support important everyday bodily functions:
- Vitamin D3 contributes to the normal function of the immune system, the maintenance of normal bones and muscles, and the normal absorption and utilization of calcium.
- Vitamin K2 MK7 contributes to the maintenance of normal bones and normal blood clotting.
This is what NN contains: Vitamin D3 + K2
- Vitamin D3 (2,500 IU per drop) – easy to dose and highly bioavailable
- Vitamin K2 MK7 – highly bioavailable, long-lasting and perfectly balanced
- Droplet shape for maximum flexibility and easy application
The combination makes it particularly easy for you to support your daily routine – with high-quality, pure ingredients in proven Nikolaus Nature quality.
Conclusion: Your vitamin D status is of great importance.
Understanding how closely vitamin D3 is linked to your daily well-being, your immune system, and many fundamental bodily functions quickly reveals that a reliable supply isn't just a "nice-to-have," but a building block for long-term health. Because our modern lifestyle makes natural production more difficult, it's worthwhile to keep an eye on your vitamin D levels, especially during the months with less sunshine. With a conscious routine, sufficient exercise in the fresh air, and high-quality products, you can effectively support your body. This gives you the best possible foundation to stay vital, balanced, and well-nourished all year round.
If you have any questions about your vitamin D routine or our products, we are always happy to help.
