Population based mean Vitamin D levels in 19 European Countries & COVID-19 Mortality

Objectives Reports early in the epidemic linking low mean national Vitamin D level with increased COVID-19 death, and until recently little research on the impact of Vitamin D deficiency on severity of COVID-19, led to this update of the initial report studying mortality up to the end of January 2021. Design and Setting Coronavirus pandemic data for 19 European countries were downloaded from Our World in Data, which was last updated on January 24, 2021. Data from March 21, 2020 to January 22, 2021 were included in the statistical analysis. Vitamin-D (25)-HD mean data were collected by literature review. Poisson mixed-effect model was used to model the data. Results European countries with Vitamin-D (25)-HD mean less than or equal to 50 have higher COVID-19 death rates as compared with European countries with Vitamin-D (25)-HD mean greater than 50, relative risk of 2.155 (95% CI: 1.068 – 4.347, p-value = 0.032). A statistically significant negative moderate Spearman rank correlation was observed between Vitamin-D (25)-HD mean and the number of COVID-19 deaths for each 14-day period during the COVID-19 pandemic time period. Conclusions The observation of the significantly lower COVID-19 mortality rates in countries with lowest annual sun exposure but highest mean Vitamin-D (25)-HD levels provides support for the use of food fortification. The need to consider re-configuring vaccine strategy due to emergence of large number of COVID-19 variants provides an opportunity to undertake such therapeutic randomized control trials. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement no funding is involved ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: not required as anonymised data I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Data available through Amar Ahmad email amar.ahmad@qmul.ac.uk