Table 1 Subject characteristics at baseline (visit 1) defined according to GDM status (visit 2)

N

303

116

–

Vitamin D deficiency

249 (82.5%)

108 (93.1%)

0.006

Age (years)

28.6 ± 5.1

30.3 ± 5.6

0.003

Age at menarche (years)

12.5 ± 1.5

12.7 ± 1.8

0.39

Age at 1st pregnancy (years)

24.3 ± 4.4

24.9 ± 5

0.35

Parity

2 (1.0–3.0)

2 (1.0–4.0)

0.03

Gestational age (weeks)

11.4 ± 2.6

11.4 ± 2.9

0.98

Pre-BMI (kg/m²)

26.4 ± 6.1

28.8 ± 6.3

0.003

BMI (kg/m²)

28.1 ± 6.7

31.2 ± 7.2

< 0.001

Waist (cm)

89.3 ± 12.6

94.8 ± 13.8

0.001

Hips (cm)

107.1 ± 11.9

110.9 ± 11.6

0.011

WHR

0.8 ± 0.1

0.9 ± 0.1

0.03

Systolic blood pressure (mmHg)

113.8 ± 13.6

111.7 ± 12.5

0.23

Diastolic blood pressure (mmHg)

66.9 ± 8.7

67.7 ± 10.2

0.63

Glucose (mmol/l)

4.7 (4.3–5.2)

5.1 (4.6–5.6)

< 0.001

Insulin (μU/mL)

8.7 (4.4–19.5)

11.5 (6.2–19.8)

0.05

HbA1c (%)

5 ± 0.4

5.2 ± 0.5

< 0.001

Triglycerides (mmol/l)

1.3 ± 0.6

1.5 ± 0.6

0.02

Total cholesterol (mmol/l)

4.9 ± 1.0

5.1 ± 1.0

0.06

HDL-cholesterol (mmol/l)

1.3 ± 0.3

1.3 ± 0.3

0.22

LDL-cholesterol (mmol/l)

3 ± 0.8

3.1 ± 0.9

0.10

Calcium (mmol/l)

2.2 ± 0.2

2.1 ± 0.1

0.66

Corrected calcium (mmol/l)

2.2 ± 0.2

2.2 ± 0.1

0.94

Albumin (g/l)

35.8 ± 4.2

35.6 ± 4

0.64

Alkaline phosphatase (mmol/l)

8.3 ± 3.1

9.6 ± 3.6

0.09

PTH (pg/ml) #

10.9 (2.1–13.3)

10.9 (2.3–12.2)

0.56

Creatinine # (μmol/l)

45.1 (27.4–55.8)

45.5 (24.0–60.6)

0.93

Vitamin D (nmol/l) at visit 1 #

25.5 (17.3–41.9)

24.4 (17.4–37.1)

0.49