Table 1

Number of individuals by age, sex, vitamin D status and case–control status

	Cases, with LBP at end of follow-up		Controls, without LBP at end of follow-up
	n	Per cent	n	Per cent
Age groups (years)
19–29	246	15	504	16
30–39	492	29	951	30
40–49	687	41	1191	38
50–55	260	15	491	16
Sex
Female	1043	62	1677	54
Male	642	38	1460	47
25(OH)D (nmol/L)
<50.0	925	55	1689	54
50.0–74.9	619	37	1126	36
≥75.0	141	8	322	10