Table 1:

Descriptive table of baseline demographic characteristics of study population by MS diagnosis

	non-Hispanic Black		non-Hispanic White
Characteristics	Cases (n=157)	Controls (n=185)*	Cases (n=23)	Controls (n=46)
Sex - n (%)
Male	80 (50.96)	91 (49.19)	19 (82.61)	38 (82.61)
Female	77 (49.04)	94 (50.81)	4 (17.39)	8 (17.39)
Age, years - median (IQR)
First serum sample collection	19 (18–23)	20 (18–23)	22 (20–28)	21.5 (20–28)
Second serum sample collection**	28 (23–33)	28 (23–33)	28 (25–34)	28 (25–34)
MS onset	28 (23–33)	NA	28 (24–35)	NA
Baseline vitamin D levels, nmol/L – median (IQR)	45 (33–64)	48 (37–63)	72 (63–89)	82 (68–97)
Baseline EBV VCA IgG seropositivity – n (%)	153 (98.08)	180 (98.90)	22 (95.65)	42 (91.30)

^*129 cases were matched on 1:1 basis whereas 28 cases on a 1:2

^**Individuals with 2 pre-symptomatic samples – unavailable for 12 Black cases and 17 controls, 9 White cases and 18 controls

Abbreviations: EBV: Epstein-Barr Virus, IQR: Inter Quartile Range, NA: not applicable