Free and Bioavailable Fractions of Vitamin D: Association with Maternal Characteristics in Brazilian Pregnant Women
Table 3
Linear regression data of variables associated with 25(OH)D3, DBP, PTH, free 25(OH)D3, and bioavailable 25(OH)D3 concentrations.
25(OH)D3 (nmol/L)
DBP (mg/L)
PTH (pg/mL)
Free 25(OH)D3 (pg/mL)
Bioavailable 25(OH)D3 (ng/mL)
Independent variable
β (95% CI)
β (95% CI)
β (95% CI)
β (95% CI)
β (95% CI)
Gestational period, wk
−0.73 (−1.31; −0.16)
−5.91 (−12.54; 0.72)
0.03 (−0.67; 0.73)
−0.01 (−0.03; 0.00)
−0.01 (−0.01; 0.00)
Prepregnancy BMI, kg/m2
0.12 (−0.33; 0.57)
5.92 (0.74; 11.09)
0.10 (−0.44; 0.65)
−0.01 (−0.03; 0.00)
−0.00 (−0.01; 0.00)
Gestational weight gain, kg
0.14 (−0.32; 0.61)
0.87 (−4.47; 5.21)
0.25 (−0.31; 0.82)
0.01 (−0.01; 0.02)
0.00 (−0.00; 0.01)
Age, y
−0.20 (−0.66; 0.27)
−0.36 (−5.68; 4.95)
−0.70 (−0.63; 0.49)
−0.01 (−0.02; 0.01)
−0.00 (−0.01; 0.00)
ITA
0.05 (−0.08; 0.174)
−0.21 (−1.67; 1.25)
0.07 (−0.09; 0.22)
0.00 (−0.00; 0.01)
0.00 (−0.00; 0.00)
SEI hand
0.30 (−0.15; 0.74)
4.97 (−0.13; 10.07)
−0.57 (−1.11; −0.30)
−0.00 (−002; 0.01)
0.00 (−0.00; −0.01)
Number of previous pregnancies
−0.52 (−2.35; 1.30)
−6.63 (−27.66; 14.39)
1.23 (−0.99; 3.45)
0.01 (−0.05; 0.07)
−0.01 (−0.02; 0.01)
Season
Spring
Ref
Ref
Ref
Ref
Ref
Summer
−4.78 (−11.21; 1.65)
−71.63 (−145.72; 2.47)
−5.11 (−12.94; 2.73)
0.00 (−0.20; 0.21)
0.00 (−0.07; 0.06)
Autumn
−9.90 (−16.14; −3.64)
−86.78 (−158.77; −14.79)
−0.80 (−8.41; 6.81)
−0.12 (−0.32; 0.08)
−0.05 (−0.11; 0.01)
Winter
−16.74 (−23.13; −10.34)
−85.39 (−159.10; −11.69)
−1.32 (−9.11; 6.48)
−0.33 (−0.53; −0.13)
−0.11 (−0.17; −0.05)
Results were obtained from multiple linear regression analysis with 25(OH)D3, DBP, PTH, free 25(OH)D3, and bioavailable 25(OH)D3 as dependent variables. ITA, individual typology angle; SEI, sun exposure index.