Table 3. Association Between Vitamin D Levels and SARS-CoV-2 Seropositivity.

Vitamin D level comparison and year	Multivariable regression analysisa		Propensity score analysisb
	OR (95% CI)	P value	OR (95% CI)	P value
<30 vs ≥30 ng/mL
2019	1.09 (0.93-1.27)	.29	1.12 (0.91-1.36)	.28
2020	1.05 (0.91-1.23)	.49	1.07 (0.88-1.29)	.52
<20 vs ≥20 ng/mL
2019	1.04 (0.88-1.22)	.66	1.04 (0.84-1.27)	.74
2020	0.93 (0.79-1.09)	.36	0.99 (0.81-1.21)	.93

Abbreviation: OR, odds ratio.

SI conversion factor: To convert vitamin D level to nanomoles per liter, multiply by 2.496.

^a Adjusted for age (continuous), sex, race/ethnicity, education, body mass index (continuous), blood pressure, smoking status, and geographical location.

^b Based on matching pairs (see the eFigure in the Supplement).