Absorb vitamin D naturally in winter: Is that even possible?

Absorbing vitamin D from the sun in winter is hardly possible in the temperate climate zone. Here you can find out why this is and how you can prevent a vitamin D deficiency.

Vitamin D is important for healthy bones and muscles and is involved in numerous metabolic processes in the body. In contrast to other vitamins, we do not necessarily have to consume vitamin D through food. Our body can produce the vitamin itself. To do this, however, it needs sufficient sunlight and especially the so-called UVB rays.

Since the sun shines significantly less in winter, many people take vitamin D as a dietary supplement in winter. This can actually make sense, but is not fundamentally necessary.

Vitamin D in winter: Too weak sunlight

In the warm seasons, the sun’s rays are intense enough for the body to produce vitamin D itself. How long you should be exposed to the sun every day to absorb enough UVB radiation varies from person to person and depends, among other things, on skin type and age.

According to the Federal Institute for Risk Assessment (BfR), the rule of thumb is: you should be in the sun for five to 25 minutes a day. A quarter of your skin should be uncovered. The RKI recommends spending half the time in the sun every day that would cause sunburn if left unprotected. How long that is depends largely on your skin color. You can learn more about this in our article on sun protection factor.

However, from October to March it is generally not possible to absorb sufficient sunlight for vitamin D production, according to the BfR. This is because the sun shines on Earth at a flatter angle during this time. This filters out more UV light.

Companies therefore advertise some high-dose preparations that are intended to guarantee a supply of vitamin D in winter. But is that really necessary?

Vitamin D in winter: How useful are capsules and tablets?

Since vitamin D is involved in so many different processes, a deficiency of the vitamin also has a holistic effect on the body. Consequences of a vitamin D deficiency include mood swings, fatigue or the development of chronic diseases, according to GEO.

But just because there isn’t enough sunlight in winter doesn’t mean you’ll develop a deficiency during this time. Because our body can store vitamin D in fat and muscle tissue, explains the RKI. So if you spend enough time in the sun in spring and summer, our body creates reserves. These can also provide you with supplies in winter when the sun is less bright.

According to GEO, there are also foods that contain vitamin D. However, these are primarily animal products such as fish, eggs, cheese and butter. When it comes to plant-based foods, the choice is significantly smaller: only avocados and some mushrooms contain vitamin D if they have received enough sun while growing.