You seldom see the sun in the autumn and winter months, but the body can absorb vitamin D even when the sky is cloudy.

Human beings take in vitamin D primarily through radiation from the sun. However, this can become a problem in the dark months.

Kassel – In autumn and winter, many people complain of being listless. In many cases, this is due to a vitamin D deficiency. If the body lacks the vitamin, the immune system is weakened. The protective effect against heart disease, diabetes, rheumatism and, more recently, Covid-19 is often weakened.

For example, science has been discussing the risk of corona infections due to a vitamin D deficiency for some time. Vitamin D, which strictly speaking is not a vitamin but a hormone, is considered essential for the human organism in medicine: “The body produces around 85 to 90 percent itself with the help of UV radiation,” explains Professor Dr. Helmut Schatz, emeritus director of the Bergmannsheil Medical University Clinic at the Ruhr University Bochum and board member of the German Society for Endocrinology. This is what the health portal of German pharmacists reports.

Vitamin D in autumn: nutrition alone is not enough for production

Vitamin D can also be taken in through food. It can be found in foods such as salmon or herring, chicken eggs, mushrooms, chanterelles, and veal or beef liver. “However, a sufficient supply of vitamin D cannot be achieved through diet alone. The most important thing is to go outside, preferably every day for about half an hour with your hands and face uncovered, ”explains Schatz.

Of course, the sun is seldom seen in the autumn and winter months, but the body can absorb vitamin D even when the sky is cloudy. The average adult should have over 50 nmol / L (20 μg / L) of vitamin D in their blood. Serum values ​​below 30 nmol / l (12 μg / l) are considered to be deficiencies.

According to the Robert Koch Institute, certain groups in the population have a higher risk of having a vitamin D deficiency than others – these include:

  • People who are seldom outdoors
  • Seniors over 65, as the self-production of vitamin D decreases with age
  • Infants who should not be exposed to direct sunlight
  • People who, for religious reasons, only go outside with their skin covered
  • People with dark skin, as it is less permeable to UV rays
  • People with chronic intestinal, liver or kidney diseases

In the video: Vitamin D deficiency is not just a winter problem

Vitamin D deficiency in autumn: experts warn against too high a dosage

According to Schatz, adults who are healthy and regularly go outside do not need to take additional vitamin D supplements. However, if you have the feeling that you are suffering from a deficiency, you should first have it checked by your family doctor, according to the specialist. However, a blood test for vitamin D is usually not covered by health insurance and must be paid for yourself in that case – the same applies to dietary supplements if they are not medically necessary.

Extreme caution is also required when taking vitamin D supplements, as too much of them can cause considerable damage to the body. “850 to 1000 international units (IU) daily are not a cause for concern, but I strongly advise against using very high-dose preparations with 5000 or 10000 IU,” warns Schatz. In individual cases, too high a dose of vitamin D, which is taken over a long period of time, can damage the kidneys and even promote heart disease.

If the body is not supplied with sufficient calcium, there is also a risk of discomfort. Tingling in the feet or even cardiac arrhythmias can indicate a deficiency. (Luisa Weckesser)