Table I.

Study population characteristics

	Gene (mRNA) expression study		MicroRNA expression study
Characteristics	High Vitamin D (≥31.7 ng/ml)*	Low Vitamin D (<25.5 ng/ml)	High Vitamin D (≥31.7 ng/ml)	Low Vitamin D (<25.5 ng/ml)
Number (N)	11	10	6	7
Age, years**	34.18 (3.9)	33.2 (5.5)	34.33 (3.1)	33.43 (2.4)
Gestational Age, weeks**	15.91 (2.2)	16.3 (2.5)	15.14 (1.9)	16.84 (2.1)
Pre-pregnancy BMI (kg/m2)**	21.58 (3.1)	23.39 (2.8)	22.87 (3.7)	26.40 (5.6)
Overweight (≥24kg/m2)	1 (10%)	3 (30%)	2 (29%)	1 (14%)
Non-Hispanic Whites	11 (100%)	10 (100%)	6 (100%)	7 (100%)
Married	11 (100%)	9 (90%)	6 (100%)	7 (100%)
Nulliparous	5 (45%)	4 (40%)	4 (66.7%)	3 (42.9%)
Gravidity**	2.64 (1.62)	2.10 (1.60)	2.17 (2.4)	2.00 (0.6)
Season of blood draw
Spring/Summer	5 (46.5)	5 (50%)	2 (33.3%)	3 (42.9%)
Fall/Winter	6 (64.5)	5 (50%)	4 (66.7%)	4 (57.1%)
Plasma 25-hydroxyvitamin D (25-[OH] D) concentrations, ng/ml**	38.84 (7.0)	22.09 (2.6)	39.22 (6.1)	22.84 (2.0)

^*mean (standard deviation), otherwise number (%)

^**Assessed by measuring maternal early pregnancy plasma 25-hydroxyvitamin D (25-[OH] D) concentrations

Abbreviations: GA=gestational age at blood draw, BMI=body mass index

^***The only statistically significant difference (p-value < 0.05) between the two groups in each experiment is the difference between vitamin D levels.