Table 2. Odds ratios (OR) and 95% confidence intervals (CI) for gestational diabetes (GDM) according to maternal plasma 25-hydroxyvitamin D (25(OH)D) concentrations in pregnancy.

25(OH)D (ng/ml)	GDM Cases	Controls	Unadjusted	Adjusted*	Adjusted**
	(N = 57)	(N = 114)	OR (95% CI)	OR (95% CI)	OR (95% CI)
All Subjects
25(OH)D (categorical variable)
Sufficient (≥30)	14	51	1.00 (referent)	1.00 (referent)	1.00 (referent)
Insufficient (20–29)	24	47	1.86 (0.86–4.01)	1.86 (0.84–4.09)	1.56 (0.69–3.52)
Deficient (<20)	19	16	4.33 (1.78–10.5)	3.74 (1.47–9.50)	2.66 (1.01–7.02)
P for trend			0.001	0.006	0.05
25(OH)D(continuous variable)
Per 5 ng/ml reduction			1.44 (1.16–1.69)	1.36 (1.11–1.69)	1.29 (1.05–1.60)
Non-Hispanic Whites
25(OH)D (categorical variable)
Sufficient (≥30)	11	45	1.00 (referent)	1.00 (referent)	1.00 (referent)
Insufficient (20–29)	16	42	1.56 (0.65–3.74)	1.58 (0.65–3.87)	1.21 (0.47–3.09)
Deficient (<20)	13	9	5.91 (2.02–17.3)	5.40 (1.78–16.4)	3.77 (1.19–11.9)
P for trend			0.002	0.005	0.04
25(OH)D (continuous variable)
Per 5 ng/ml reduction			1.44 (1.16–1.79)	1.44 (1.11–1.79)	1.29 (1.05–1.69)

Vitamin D deficiency was defined using cut-points given by Holick, MF ([reference 1]).

^*Adjusted for maternal age, race/ethnicity and family history of diabetes.

^**Adjusted for maternal age, race/ethnicity and family history of diabetes as well as pre-pregnancy body mass index.