Obesity and smoking being a strong contributor to severity of symptoms has been stated and reported for months.
Same thing for vitamin D and sunlight respectively
https://www.nature.com/articles/s41598-020-77093-z
Analysis of vitamin D level among asymptomatic and critically ill COVID-19 patients and its correlation with inflammatory markers | Scientific Reports
COVID-19 is characterized by marked variability in clinical severity. Vitamin D had recently been reviewed as one of the factors that may affect the severity in COVID-19. The objective of current study is to analyze the vitamin D level in COVID-19 patients and its impact on the disease severity. Aft..
https://www.nature.com/articles/s41598-020-77093-z
