The autumn COVID-19 boost dates in Europe are linked to latitudes and not to temperatures pointing vitamin D as a contributing factor
Received date: 10th November 2020
Purpose: Determining the triggering factor of the sudden boost of the daily new COVID-19 cases arising in most European countries during 2020 Autumn. Methods: The dates of the boost were determined using a fitting of the two last months reported daily new cases in 18 European countries of latitude ranging from 39° to 62°. Results: The study proves no correlation between the country boost date and its 2 weeks preceding temperature, but shows an impressive linear correlation with its latitude. The country boost date corresponds to the time when its sun UV daily dose drops below ≈30% of that of 0° latitude. Conclusions: The previous studies, reporting a vitamin D blood level impact, compared COVID-19 severity between different patients populations and so can hardly discriminate whether the vitamin D blood level is a real factor of covid-19 severity or only a marker of another weakness being the primary severity factor. In contrary, the date of the boost is an intrapopulation observation and can thus only be triggered by a parameter globally affecting the population, i.e. the sun UV daily dose decreases. This result evidences that low vitamin blood D level is a contributing factor of COVID-19 severity.
This is an abstract of a preprint hosted on a preprint server, which is currently undergoing peer review at Scientific Reports. The findings have yet to be thoroughly evaluated, nor has a decision on ultimate publication been made. Therefore, the results reported should not be considered conclusive, and these findings should not be used to inform clinical practice, or public health policy, or be promoted as verified information.