Vitamin D Deficiency is Associated with Higher Risks for SARS-CoV2 Infection and COVID-19 Severity: A Retrospective Case-Control Study

This large observational study found an association between vitamin D deficiency and risk of COVID–19 infection and disease severity.

• An inverse correlation was demonstrated between the level of vitamin D and the risks of SARS-CoV-2 infection and of severe disease in those infected. 
• Patients with very low vitamin D levels (< 30 nmol/L) had the highest risks for SARS-CoV-2 infection and also for severe COVID-19 when infected.

Individuals with COVID–19 and those without from the largest health organization in Israel.

• There was a wide range of times between when vitamin D levels were measured and before eventual infection or hospitalization. 
• The authors did not have information on treatment with vitamin D supplements during the study period. 

In this large observational population study, we show a significant association between vitamin D deficiency and the risks of SARS-CoV-2 infection and severe disease in those infected.

• This retrospective study was conducted to evaluate the association between vitamin D levels and the risks of SARS-CoV-2 infection and severe disease in those infected. 
• 2 matched case control groups of individuals for which vitamin D levels and body mass index (BMI) were available before the pandemic: group (A), in which 41,757 individuals with positive SARS-CoV-2 PCR tests were matched with 417,570 control individuals without evidence of infection, and group (B), in which 2533 patients hospitalized in severe condition for COVID-19 were matched with 2533 patients who were tested positive for SARS-CoV-2, but were not hospitalized. 
• Conditional logistic models were fitted in each of the groups to assess the association between vitamin D levels and outcome.

Israel A, Cicurel A, Feldhamer I, Stern F, Dror Y, Giveon SM, Gillis D, Strich D, Lavie G. Vitamin D deficiency is associated with higher risks for SARS-CoV-2 infection and COVID-19 severity: a retrospective case-control study. Intern Emerg Med. 2022 Jun;17(4):1053-1063. doi: 10.1007/s11739-021-02902-w. Epub 2022 Jan 9. PMID: 35000118; PMCID: PMC8742718.