Table 3.
Variables | Vitamin D | Vitamin A | ||||
---|---|---|---|---|---|---|
β | 95%CI | p | β | 95%CI | p | |
Age (overall)a | 0.16 | 0.07–0.26 | <0.001 | 0.004 | 0.004–0.005 | <0.001 |
Age (non–linear)b | 0.033 | <0.001 | ||||
Season | ||||||
Spring | 1.99 | 1.49–2.50 | <0.001 | 0.03 | 0.02–0.03 | <0.001 |
Summer | 9.73 | 9.21–10.25 | <0.001 | −0.01 | −0.02 to −0.01 | <0.001 |
Autumn | 5.78 | 5.24–6.31 | <0.001 | −0.02 | −0.03 to −0.02 | <0.001 |
Winter | ref | ref | ||||
Gestational trimester | ||||||
1st trimester | ref | ref | ||||
2nd trimester | 3.35 | 2.93–3.77 | <0.001 | −0.0003 | −0.004 to 0.003 | 0.864 |
3rd trimester | 5.53 | 5.08–5.99 | <0.001 | −0.051 | −0.054 to −0.048 | <0.001 |
Region | ||||||
Shaanxi | 10.7 | 10.1–11.35 | <0.001 | 0.001 | −0.005 to 0.006 | 0.843 |
Ningxia | – | 0.03 | 0.02–0.04 | <0.001 | ||
Qinghai | ref | 0.02 | 0.01–0.02 | <0.001 | ||
Shanxi | – | ref |
The four seasons are defined by date: spring, from March to May; summer, from June to August; autumn, from September to November; winter, from December to February.
overall association;
non-linear association.