evidence: There were data sets from 10 countries that fitted the criteria and were analyzed. Severe vitamin D deficiency was defined as 25(OH)D less than 25 nmol/L (10 ng/dL). Pearson correlation analysis between death rate per million of population from coronavirus disease 2019 (COVID-19) and prevalence of severe vitamin D deficiency showed a strong correlation with r = 0.79, p = 0.007. Over time, correlation strengthened, and r coefficient asymptotically increased. After adjusting for countries’ age structure and per capita health expenditures, multiple linear regression analysis showed that higher prevalence of severe vitamin D deficiency is associated with increased mortality. Each 1% increase in prevalence increased deaths by 55 per million (95% confidence interval, CI 8–102), p = 0.03. [...] Data collected shows a strong and significant correlation between prevalence of severe Vitamin D deficiency and COVID-19 deaths per million in European countries. The correlation is asymptotically getting stronger over time, making it even less likely to be caused by a random chance. This is consistent with US and UK trends that show the mortality rate from COVID-19 is higher in dark-skinned and obese individuals than in general population, as these individuals are at higher risk for vitamin D deficiency. [...] There is a strong correlation between prevalence of severe vitamin D deficiency and the mortality rate per million from COVID-19 in the European countries. The authors recommend for physicians to universally screen for vitamin D deficiency, and recommend further investigation of vitamin D supplementation in randomized control studies, which may lead to possible treatment or prevention of COVID-19.