Association of Vitamin D Status with COVID-19 Infection and Mortality in the Asia Pacific region: A Cross-Sectional Study

This population study found a relationship between vitamin D levels and the number of COVID-19 cases, but not deaths in Asia Pacific countries. While the study demonstrated a correlation between COVID-19 infection and vitamin D levels, more studies are needed to determine the role of vitamin D levels and COVID-19 transmission.   

Population data was collected for 37 Asia Pacific countries, defined as per the Asia Pacific Observatory on Health Systems and Policies, WHO Regional Office for South–East Asia. 

Vitamin D levels and COVID-19 cases and deaths published between September 2000 and September 15, 2020. 

• The highest number of cases per million and of deaths per million were reported in Qatar and Iran, respectively. 
• The fewest number of cases per million and of deaths per million were reported in Vietnam and Taiwan, respectively.  
• The highest concentration of vitamin D, as well as the lowest number of deaths per million, were reported in Taiwan. Bahrain had the lowest reported concentration of vitamin D. 
• Mean levels of Vitamin D were found to have a significant association with the number of cases per million Mean levels of vitamin D were found to have a non- significant association with the number of deaths per million COVID-19. 

• Important variables that were not considered in this study are human behavior and control measures, like masking, social distancing, lock-down measures and travel bans.  
• Early and rigorous restrictions implemented by countries like Taiwan that were adhered to by their citizens, likely had a major impact on preventing the growth of COVID-19 cases and deaths.  
• Island nations that are able to restrict travel into their countries likely also had an advantage in preventing disease transmission. 
• This study shows a correlation between COVID-19 cases and vitamin D levels but does not prove causation. It provides a working hypothesis that requires the role of vitamin D in COVID–19 disease transmission and progression to be rigorously studied in clinical trials. 

The association observed between higher vitamin D levels and fewer COVID-19 cases in the Asia Pacific region points to the possible protective effect of vitamin D in blunting the infectivity of COVID-19. Due to the multitude of factors that affect COVID-19 infectivity and mortality, adequately designed population-based prospective studies are needed to understand the prophylactic efficiency of Vitamin D. The evidence that emerges from such studies would help in defining policies regarding the supplementation of populations with vitamin D.

• An inclusive search of the literature was performed for studies on vitamin D levels and COVID-19 cases and deaths for Asia Pacific countries published in English between September 2000 and September 15, 2020 using the PubMed and Google Scholar databases. References in the relevant articles were also searched to check for other eligible articles. 
• Asia Pacific countries were defined as per the Asia Pacific Observatory on Health Systems and Policies, WHO Regional Office for South–East Asia.  
• Data for Vitamin D levels were obtained for 37 countries, which were included in the analysis. If no vitamin D data was available, the country was excluded. 

Yadav D, Birdi A, Tomo S, Charan J, Bhardwaj P, Sharma P. Association of Vitamin D Status with COVID-19 Infection and Mortality in the Asia Pacific region: A Cross-Sectional Study. Indian J Clin Biochem. 2021 Feb 3:1-6. doi: 10.1007/s12291-020-00950-1. Epub ahead of print. PMID: 33551585; PMCID: PMC7854023. https://pubmed.ncbi.nlm.nih.gov/33551585/