Sunlight and vitamin D in the prevention of coronavirus disease (COVID-19) infection and mortality in the United States

Abstract

<title>Abstract</title> The coronavirus disease (COVID-19) is an infectious disease caused by the most recently discovered coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aims to investigate associations between sunlight and vitamin D, using latitude as an indicator, with COVID-19 cases and related deaths in the United States. General regression and Chi-square test were used to examine the associations between latitude and COVID-19 cases and deaths. The analyses indicated that latitudes were marginally associated with cases (p = 0.0792) and deaths (p = 0.0599), with an increase of 2491 cases and 189 deaths of the total numbers in the mainland of US for every unit of increase of the latitude. When the states were classified into high latitude (&gt;N 370) and low latitude (&lt;N 370) groups, both the cases (702 vs 255 cases/100k population) and deaths (43 vs 11 deaths/100k population) were significantly different (p &lt; 0.001) between the two categories. The results suggested that sunlight and vitamin D, with latitude as an indicator, might be associated with decreased risks for both COVID-19 cases and deaths. These findings warranted urgent needs of large cohort, clinical and pre-clinical studies to assess the impact of VD on the prevention of COVID-19.