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August 10, 2025
Lena Sämann
Tiredness, muscle aches, and frequent colds in autumn? These symptoms can indicate a vitamin D deficiency caused by less sunlight. Discover effective strategies from nutrition to supplementation to stay healthy through the dark season.
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Autumn not only brings colorful leaves and cooler temperatures, but also a widespread health issue: vitamin D deficiency. As the days get shorter and the hours of sunshine decrease, our bodies can no longer produce enough vitamin D. Learn how to recognize a vitamin D deficiency in time and effectively prevent it.
Vitamin D, also known as the "sunshine vitamin," is a fat-soluble vitamin that plays a central role in our health . It regulates calcium and phosphate metabolism and is essential for strong bones and teeth. In addition, vitamin D supports the immune system, muscle function, and can even influence mood.
What is particularly remarkable is that our body can produce vitamin D itself – but only under the influence of UV-B radiation from the sun. This ability makes us particularly susceptible to a deficiency during the sun-poor autumn and winter.
From September onwards, the hours of sunshine decrease drastically. The weaker UV-B radiation is often no longer sufficient to stimulate adequate vitamin D synthesis in the skin. Even in sunny autumn weather, the sun is too low in the sky to provide enough UV-B rays.
In autumn, we spend significantly more time indoors. Warm clothing also covers large areas of skin that would normally be available for vitamin D production.
The body can store vitamin D in fat and muscle tissue. However, these reserves from the summer months are usually depleted by autumn, especially if the summer was not very sunny.
A vitamin D deficiency develops gradually and is often overlooked because the symptoms are non-specific. Pay attention to the following warning signs:
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If a vitamin D deficiency remains untreated, more severe problems can arise:
Certain groups of people have an increased risk of vitamin D deficiency:
You can still get vitamin D in autumn:
Although only a few foods naturally contain vitamin D, you can optimize your intake:
Fatty fish:
Other Vitamin D sources:
If sunlight and diet are not enough, supplements can be helpful:
Recommended dosages:
Important notes:
Outdoor exercise:
Living space optimization:
A professional review of your vitamin D status is the best way to prevent it specifically:
The 25(OH)D test:
When to see a doctor:
Vitamin D plays an important role in immune function. Adequate supply can help reduce the risk of colds and flu infections – especially important in the emerging cold season.
Autumn depression or seasonal affective disorder (SAD) is often directly related to vitamin D deficiency. Targeted prevention can also stabilize mood during the darker months.
As natural vitamin D production is limited in autumn and winter, it is particularly important to support calcium absorption and maintain bone health.
Vitamin D deficiency in autumn is a widespread but avoidable issue. By combining conscious sun exposure, a diet rich in vitamin D, and, if necessary, sensible supplementation, you can optimally support your health even in the darker months.
It's best to start prevention now – your body will thank you with more energy, a better mood, and a stronger immune system. However, if symptoms persist or if you are unsure about the optimal dosage, you should always seek professional medical advice.
Remember: A balanced approach with regular monitoring of vitamin D levels is key to successful prevention. This way, you can navigate the autumn and winter months strong and healthy.
