Less vitamin D deficiency after sunny summers
Hall. UKH. Autumn is just around the corner. The shorter days with fewer hours of sunshine are also noticeable and many people think about their vitamin D balance. The University Medicine Halle has again analyzed the vitamin D values, which were measured in a total of 13,406 patients over a period of six years. The conclusion: extreme summers improved the vitamin D levels in Central Germany.
An adequate supply of vitamin D is important for a healthy body. If you want to know your values exactly, you have to have the concentration of the vitamin D precursor molecule in your blood determined. From a value below 50 nmol/liter, the supply is considered suboptimal, below 30 nmol/liter as deficient. Values that are too low can have a negative effect on bone health, among other things. The vitamin D requirement is largely covered by the body’s own production in the skin. This requires UV-B radiation from sunlight, which in our latitudes is only sufficiently available from March to October. At the beginning of autumn, many people take food supplements out of concern that their own production is no longer sufficient.
The central laboratory of the University Medicine Halle has compiled the vitamin D readings from 13,406 blood measurements over six years and compared them with the actual hours of sunshine from the German Weather Service. “We process up to 1,600 patient samples every day,” says Dr. Beatrice Ludwig-Kraus, head of the central laboratory at the University Medicine Halle. “The nice thing about this study was that no one had to take extra blood for it, the data was already there.” The work in the central laboratory also includes regular checks to ensure that the devices are correctly calibrated: “One day I noticed that the mean value of the vitamin D precursor has increased in 2018 compared to previous years. When the effect was also evident in 2019, we became curious,” explains Dr. Bernhard Kraus, clinical chemist in the central laboratory and first author of the study. The result: In the drought years of 2018 and 2019, the median blood value was 10 nmol/liter higher than in the four previous years without extreme summer. This reduced the proportion of patients with suboptimal vitamin D supply by 10% on average.
Regardless of the intensity of the summer, the vitamin D level drops significantly in the autumn months and reaches its minimum in January to March. To prevent vitamin D deficiency, the Robert Koch Institute recommends going out in the sun three times a week from March to October around noon for around 15 minutes with your face, arms and legs free. Dietary supplements can also help in the winter months, but should be dosed with care and professional advice. Because a vitamin D overdose by means of preparations can cause undesirable health side effects. Fortunately, an unhealthy oversupply via skin production or through food is not possible.