From a biological point of view, vitamin D deficiency in humans (and not just in humans) is not a phenomenon of our time but a thousand-year-old strain on Europe. Nowhere else in the world do so many people live so far from the equator as in Europe. The migration of our ancestors to Europe was promoted by the warming effects of the Gulf Stream on the European climate. The reduction in skin pigmentation could only partially improve the vitamin D supply. The so-called "Scottish Paradox" also applies in principle to most regions of Central and Northern Europe. Civilization has finally pushed the conditions further (habitation, clothing, customs, etc.). Among the Vikings in Greenland, this persistent vitamin D deficiency and concomitant health as a result of progressive inbreeding, led to the extinction of this isolated population. Low UVB irradiation (additionally restricted by the advised avoidance of the sun due to the risk of melanoma) and the limited possibility of a supply of vitamin D via food (in the best case approx. 10% possible) result in the widespread vitamin D deficiency in Europe. Although the natural conditions with regard to the sun exposure between Northern Germany and Southern Scandinavia are not so different, in contrast to Germany, foods in Scandinavia are enriched with vitamin D in order to guarantee a basic supply of the vitamin D to the population. Thus the vitamin D level in blood serum of many Swedes is higher than in the population of Northern Germany. The climatic conditions in Europe will have a particularly strong impact on the numerous immigrants with a higher melanin content in the skin in the coming years.