Table 3. Odds ratios (OR) and 95% confidence intervals (CI) for gestational diabetes (GDM) according to both maternal plasma 25-Hydroxyvitamin D deficient status and pre-pregnancy overweight status.

Vitamin D deficiency*	Overweight**	GDM Cases	Controls	Unadjusted OR (95% CI)	Adjusted1 OR (95% CI)
		(N = 57)	(N = 114)
No	No	22	75	1.00 (referent)	1.00 (referent)
Yes	No	7	9	2.65 (0.89–7.93)	2.36 (0.75–7.43)
No	Yes	16	23	2.37 (1.07–5.25)	2.24 (0.99–5.08)
Yes	Yes	12	7	5.84 (2.05–16.6)	4.93 (1.63–14.9)
P value for interaction term				0.93	0.93

^*Vitamin D deficiency is defined as maternal plasma 25-Hydroxyvitamin D concentrations <20 ng/ml (Holick MF, [reference 1]).

^**Overweight is defined as pre-pregnancy body mass index (BMI) ≥25 kg/m².

¹Adjusted for maternal age, race/ethnicity, and family history of diabetes.