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Table 2 Neonatal characteristics according to maternal pre-pregnancy BMI and postpartum vitamin D status

From: Maternal excess adiposity and serum 25-hydroxyvitamin D < 50 nmol/L are associated with elevated whole body fat mass in healthy breastfed neonates

Characteristic1

All

25(OH)D < 50 nmol/L

25(OH)D ≥ 50 nmol/L

P-value2

BMI < 25 kg/m2 (n = 24)

BMI ≥ 25 kg/m2 (n = 21)

BMI < 25 kg/m2 (n = 69)

BMI ≥ 25 kg/m2 (n = 28)

25(OH)D

BMI

25(OH)D*BMI

Birth

 Gestational age, wk

39.64 (39.5, 39.8)

39.9 (39.4, 40.4)

39.7 (39.2, 40.1)

39.7 (39.4, 39.9)

39.3 (38.9, 39.8)

0.13

0.13

0.90

 Sex, n (%)

  Male

83 (58.5)

13 (54.2)

14 (66.7)

40 (58.0)

16 (57.1)

0.002

0.01

0.04

  Female

59 (41.5)

11 (45.8)

7 (33.3)

29 (42.0)

12 (42.9)

0.003

0.01

0.47

 UVB period3, n (%)

  Synthesizing

83 (58.5)

14 (58.3)

9 (42.9)

43 (62.3)

17 (60.7)

< 0.0001

0.001

0.34

  Non-synthesizing

59 (41.5)

10 (41.7)

12 (57.1)

26 (37.7)

11 (39.3)

0.05

0.09

0.06

 Weight, kg

3.4 (3.3, 3.5)

3.4 (3.3, 3.6)

3.5 (3.3, 3.7)

3.3 (3.3, 3.4)

3.4 (3.2, 3.6)

0.12

0.44

0.69

 Weight z score

0.2 (0.0, 0.3)

0.3 (−0.1, 0.7)

0.3 (− 0.1, 0.7)

0.1 (− 0.1, 0.2)

0.2 (− 0.1, 0.5)

0.20

0.68

0.54

 Serum 25(OH)D, nmol/L

44.5 (41.3, 47.6)

29.3 (24.8, 33.7)

26.6 (23.0, 30.2)

54.3 (50.0, 58.6)

46.7 (40.8, 52.5)

< 0.0001

0.07

0.38

Postnatal visit

 Age, mo

0.7 (0.6, 0.8)

0.7 (0.6, 0.8)

0.6 (0.5, 0.8)

0.7 (0.7, 0.8)

0.7 (0.6, 0.8)

0.37

0.25

0.51

 Weight, kg

4.0 (3.9, 4.1)

4.1 (3.8, 4.3)

3.9 (3.7, 4.2)

3.9 (3.8, 4.1)

4.0 (3.8, 4.2)

0.61

0.68

0.29

 Weight z score

−0.1 (− 0.2, 0.0)

0.1 (−2.0, 0.5)

− 0.01 (− 0.4, 0.4)

−0.2 (− 0.4, − 0.03)

−0.02 (− 0.4, 0.3)

0.23

0.86

0.28

 Length, cm

53.1 (52.7, 53.4)

53.8 (52.9, 54.8)

53.0 (52.2, 53.8)

52.9 (52.4, 53.3)

53.0 (52.1, 53.9)

0.22

0.34

0.19

 Length z score

−0.01 (− 0.2, 0.1)

0.4 (− 0.1, 0.8)

0.1 (− 0.3, 0.4)

−0.2 (− 0.4, 0.1)

−0.03 (− 0.4, 0.3)

0.06

0.57

0.20

 Head circumference, cm

36.4 (36.2, 36.6)

36.5 (35.9, 37.0)

36.5 (35.9, 37.0)

36.3 (36.1, 36.6)

36.7 (36.2, 37.2)

0.95

0.40

0.43

 Head circumference z score

0.1 (−0.02, 0.3)

0.2 (− 0.3, 0.6)

0.3 (− 0.1, 0.7)

−0.03 (− 0.2, 0.2)

0.3 (0.01, 0.7)

0.71

0.13

0.43

 Serum 25(OH)D, nmol/L

54.7 (51.9, 57.5)

45.1 (40.3, 49.9)

42.3 (34.5, 50.1)

61.9 (57.9, 65.9)

54.5 (49.3, 59.7)

< 0.0001

0.08

0.42

 Skin tone4, n (%)

  F I-III

110 (77.5)

17 (70.8)

14 (66.7)

59 (85.5)

20 (71.4)

< 0.0001

< 0.0001

0.04

  F IV-VI

32 (22.5)

7 (29.2)

7 (33.3)

10 (14.5)

8 (28.6)

0.48

0.72

0.75

  1. Abbreviations: 25(OH)D 25-hydroxyvitamin D, F Fitzpatrick, UVB Ultraviolet B
  2. 1Data are mean (lower and upper 95% confidence limits) or n (%)
  3. 2Data were compared using a linear fixed effect model for continuous variables followed by post hoc Tukey’s tests with Tukey-Kramer adjustment for multiple comparisons; and Chi-square or Fisher exact tests for categorical variables (using frequency procedure to create 3-way cross tabulation tables; categorical variables were used in the model to stratify the crosstabulation tables followed by the last two variables: maternal 25(OH)D*pre-pregnancy BMI, creating two 2-way tables of 25(OH)D and pre-pregnancy BMI, for each level of the categorical variables)
  4. 3Vitamin D synthesizing: April 1st-October 31st or vitamin D non-synthesizing: November 1st-March 31st
  5. 4Classified based on Fitzpatrick descriptions: F I-III (light) and F IV-VI (dark) [30, 31]
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BMC Pregnancy and Childbirth

ISSN: 1471-2393

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