. 2023 Jan 31;12(1):77–89. doi: 10.7762/cnr.2023.12.1.77

Table 4. Main characteristics of included article evaluated the association between folate and respiratory-related viral infection.

Authors	Study design	Sample size	Biomarker	Dose	Result^*	Mean or range of age (yr)	Target
Acosta-Elias and Espinosa-Tanguma (2020) [58]	Cross-sectional	94, pregnant women	The likelihood of requiring hospitalization for SARS-CoV-2 infection	-	+	-	COVID-19
		137, non-pregnant in 2009 A-H1N1 pandemic					A-H1N1 pandemic
		908 of those patients were non-pregnant women in reproductive age
		55, pregnant women in COVID-19 pandemic
Hamer et al. (2009) [59]	Cross-sectional	352	Vitamins and minerals concentration	-	+	Men, 75.8	Respiratory infections
Hamer et al. (2009) [59]	Cross-sectional	352	Vitamins and minerals concentration	-	+	Women, 73.7	Respiratory infections
Itelman et al. (2020) [60]	Cohort	162	Blood folate concentration	-	+	52	COVID-19

COVID-19, coronavirus disease 2019; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

^*+: significant effect on the prevention of respiratory-related viral infection; −: no significant effect on the prevention of respiratory-related viral infection.