Table 1 General characteristics of the study population (n = 532) according to tertiles of 25-hydroxyvitamin D₂ and month-specific tertiles of 25-hydroxyvitamin D₃

T1 (n = 177, 0.08-1.19 nmol/L)

T2 (n = 178, 1.20-2.09 nmol/L)

T3 (n = 177, 2.10-20.2 nmol/L)

T1 (n = 177, 8–86 nmol/L)^d

T2 (n = 177, 27–100 nmol/L)^d

T3 (n = 178, 43–169 nmol/L)^d

Age (years)

40.5 ± 10.5

39.0 ± 9.8

39.2 ± 10.0

40.9 ± 10.4

39.5 ± 10.3

38.2 ± 9.4

Male sex (%)

51

47

55

53

52

49

Body mass index (kg/m²)

24.5 ± 3.4

24.7 ± 3.1

24.3 ± 3.3

24.7 ± 3.7

24.5 ± 3.1

24.2 ± 2.8

HbA_1c (%) (mmol/mol)

8.7 ± 1.7 (72 ± 19)

8.5 ± 1.7 (69 ± 19)

8.5 ± 1.5 (69 ± 16)

9.0 ± 1.8 (75 ± 20)

8.4 ± 1.5 (68 ± 16)

8.2 ± 1.5 (66 ± 16)

Duration of diabetes (years)

22.9 ± 9.0

20.5 ± 9.7

20.9 ± 9.3

22.8 ± 9.2

22.2 ± 9.9

19.4 ± 8.8

Total cholesterol (mmol/L)

5.4 ± 1.4

5.4 ± 1.1

5.1 ± 1.1

5.4 ± 1.3

5.2 ± 1.1

5.3 ± 1.2

LDL cholesterol (mmol/L)

3.2 ± 1.2

3.1 ± 1.0

3.2 ± 1.0

3.2 ± 1.1

3.1 ± 1.0

3.2 ± 1.1

HDL cholesterol (mmol/L)

1.6 ± 0.5

1.6 ± 0.4

1.6 ± 0.4

1.6 ± 0.4

1.6 ± 0.4

1.7 ± 0.4

Total-HDL-cholesterol-ratio

3.7 ± 1.3

3.5 ± 1.4

3.3 ± 1.0

3.7 ± 1.5

3.4 ± 1.1

3.3 ± 1.1

Triacylglycerols (mmol/L)

1.0 (0.8-1.4)

1.0 (0.7-1.4)

0.9 (0.7-1.2)

1.0 (0.7-1.5)

1.0 (0.8-1.4)

0.9 (0.7-1.2)

Smoking (never/ex/current, %)

39/32/29

39/32/29

42/24/34

37/28/35

42/30/28

41/30/29

Physical activity (0/≤median^a/>median, %)

68/17/15

59/20/21

60/21/19

74/14/12

63/20/17

50/25/25

Alcohol intake (0/≤70 g per wk/>70 g per wk, %)

16/53/31

19/53/28

10/57/33

21/53/26

13/56/31

10/55/35

Systolic blood pressure (mmHg)

127 ± 22

121 ± 19

120 ± 18

125 ± 21

121 ± 20

123 ± 18

Diastolic blood pressure (mmHg)

76 ± 11

75 ± 12

74 ± 11

76 ± 12

73 ± 11

76 ± 11

Use of antihypertensive medication (%)

45

31

19

36

33

26

Use of hormone replacement therapy (% women)

14

11

10

11

8

15

Use of oral contraceptive therapy (% women)

39

42

47

27

49

50

Estimated glomerular filtration rate (mL/min)

97 (77–109)

103 (88–114)

104 (91–113)

102 (82–112)

102 (86–112)

101 (89–112)

C-reactive protein (mg/L)

1.1 (0.5-2.7)

1.0 (0.4-2.5)

1.1 (0.4-2.4)

1.4 (0.5-3.5)

0.9 (0.4-2.3)

0.9 (0.4-2.4)

Interleukin-6 (pg/mL)

2.1 (1.5-4.0)

1.8 (1.1-3.0)

1.8 (1.2-3.1)

2.3 (1.5-4.4)

1.9 (1.2-3.0)

1.6 (1.1-2.8)

Tumour necrosis factor-α (pg/mL)

3.2 (2.3-4.6)

2.7 (2.0-3.3)

2.6 (2.0-3.2)

3.1 (2.2-4.3)

2.7 (2.1-3.5)

2.7 (2.1-3.4)

Low-grade inflammation score (SD)^b

0.27 ± 1.00

−0.13 ± 0.99

−0.14 ± 0.97

0.26 ± 1.10

−0.11 ± 0.87

−0.14 ± 0.97

Soluble E-selectin (ng/mL)

36 ± 20

32 ± 11

35 ± 12

36 ± 16

35 ± 16

32 ± 13

Soluble vascular cell adhesion molecule-1 (ng/mL)

451 ± 174

391 ± 97

387 ± 98

438 ± 169

399 ± 106

393 ± 103

Endothelial dysfunction score (SD)^c

0.30 ± 1.32

−0.22 ± 0.74

−0.08 ± 0.76

0.21 ± 1.15

−0.04 ± 0.97

−0.17 ± 0.82

Albuminuria (normo/micro/macro, %)

45/13/42

65/17/18

73/17/10

52/14/34

58/20/22

74/13/13

Retinopathy (none/non-proliferative/proliferative, %)

34/30/36

49/27/24

49/25/26

34/33/33

44/28/28

54/21/25

Cardiovascular disease (%)

21

29

24

28

27

20

25-hydroxyvitamin D₂ (nmol/L)

0.8 (0.6-1.0)

1.5 (1.4-1.8)

2.8 (2.4-3.9)

1.4 (0.9-2.5)

1.6 (1.1-2.4)

1.6 (1.1-2.4)

25-hydroxyvitamin D₃ (nmol/L)

46 (28–73)

58 (37–75)

49 (33–74)

27 (21–38)

48 (39–67)

77 (62–98)