Vitamin D3 Supplementation at 5000 IU Daily for the Prevention of Influenza-like Illness in Healthcare Workers: A Pragmatic Randomized Clinical Trial.

Vitamin D supplementation has been shown to reduce the incidence of acute respiratory infections in populations at risk. The COVID-19 pandemic has highlighted the importance of preventing viral infections in healthcare workers. The aim of this study was to assess the hypothesis that vitamin D3 supplementation at 5000 IU daily reduces influenza-like illness (ILI), including COVID-19, in healthcare workers. We conducted a prospective, controlled trial at a tertiary university hospital. A random group of healthcare workers was invited to receive 5000 IU daily vitamin D3 supplementation for nine months, while other random healthcare system workers served as controls. All healthcare workers were required to self-monitor and report to employee health for COVID-19 testing when experiencing symptoms of ILI. COVID-19 test results were retrieved. Incidence rates were compared between the vitamin D and control groups. Workers in the intervention group were included in the analysis if they completed at least 2 months of supplementation to ensure adequate vitamin D levels. The primary analysis compared the incidence rate of all ILI, while secondary analyses examined incidence rates of COVID-19 ILI and non-COVID-19 ILI. Between October 2020 and November 2021, 255 healthcare workers (age 47 ± 12 years, 199 women) completed at least two months of vitamin D3 supplementation. The control group consisted of 2827 workers. Vitamin D3 5000 IU supplementation was associated with a lower risk of ILI (incidence rate difference: -1.7 × 10-4/person-day, 95%-CI: -3.0 × 10-4 to -3.3 × 10-5/person-day, p = 0.015) and a lower incidence rate for non-COVID-19 ILI (incidence rate difference: -1.3 × 10-4/person-day, 95%-CI -2.5 × 10-4 to -7.1 × 10-6/person-day, p = 0.038). COVID-19 ILI incidence was not statistically different (incidence rate difference: -4.2 × 10-5/person-day, 95%-CI: -10.0 × 10-5 to 1.5 × 10-5/person-day, p = 0.152). Daily supplementation with 5000 IU vitamin D3 reduces influenza-like illness in healthcare workers.

Correlation of Country Characteristics and Government Response Measures With COVID-19 Mortality During the First Phase of the Global COVID-19 Pandemic: A Worldwide Ecological Study.

Introduction It is valuable to know if country demographic, educational, healthcare and other socioeconomic factors were correlated with the COVID-19 mortality rate during the initial phase of the coronavirus disease 2019 (COVID-19) worldwide pandemic (January 1st - August 31st, 2020). Similarly, it is worthwhile understanding whether a country's geographic location or the measures instituted by governments, such as lockdowns and mask-wearing, were associated with an increased or decreased mortality rate. Materials and methods To assess these correlations, we conducted an ecologic study of 178 countries using time-matched data from the Social Progress Index (www.socialprogress.org, produced by the Social Progress Imperative), population data from the World Bank (data.worldbank.org), government response indices from Our World In Data (ourworldindata.org/policy-responses-covid), and COVID-19 mortality data from the Johns Hopkins University CSSE COVID-19 Data repository (github.com/CSSEGISandData/COVID-19), accessed on November 22nd, 2020. Pearson correlation coefficients were derived between potential predictors and countries' COVID-19 population-adjusted crude mortality rates. Select variables were entered in a multivariable regression model. Countries with no data in the social progress index database or those with no COVID-19 cases were excluded (20 in total).  Results The highest positive correlations were found between the proportion of the population older than 75 (Pearson correlation coefficient 0.321), country distance from the equator (0.267), gross domestic product per capita (0.218), health and wellness score (0.388), water and sanitation score (0.384), environmental quality (0.237), and the days between the first reported COVID-19 case and the initial government response (0.238). A previously unreported and unexpected negative correlation was found between gender parity in secondary education attainment and COVID-19 mortality (-0.290). Peak mask-wearing ranging from 'recommended' to 'required outside the home at all times was extremely weakly correlated with lower COVID-19 mortality (-0.046). Conclusions Crude COVID-19 mortality rates during the first phase of the pandemic in 2020, during which no vaccine or specific treatment was available, were higher in wealthier countries that were further away from the equator and had a higher health and wellness score according to the Social Progress Imperative. They were also higher the longer governments delayed their initial response. Gender parity in secondary education and stringency of mask-wearing guidelines were correlated with lower mortality, though the latter correlation was extremely weak. Our findings are consistent with previously published correlations. The correlation between crude COVID-19 mortality rates and gender parity in secondary education has not been previously reported.