Table 2. OR of high insulin resistance (HOMA-IR >75 percentile) according to serum 25(OH)D levels.

25(OH)D, ng/mL	Model 1a		Model 2b		Model 3c
	OR (95% CI)	P for trendd	OR (95% CI)	P for trendd	OR (95% CI)	P for trendd
≥14.3	Reference	0.001	Reference	0.001	Reference	0.042
9.7 to <14.3	1.31 (1.00–1.71)		1.37 (1.04–1.80)		1.19 (0.88–1.62)
<9.7	1.57 (1.21–2.04)		1.65 (1.26–2.16)		1.37 (1.01–1.86)

HOMA-IR, homeostasis model assessment insulin resistance; 25(OH)D, 25-hydroxyvitamin D; OR, odds ratio; CI, confidence interval.

^aModel 1 was the unadjusted model, ^bModel 2 adjusted for age and gender, ^cModel 3 adjusted for age, gender, waist circumference, alcohol consumption, smoking status, physical exercise, season, and cohorts, ^dP for trend indicates the comparison of prevalence of high insulin resistance according to serum 25(OH)D levels.