Table 2 Multiple logistic regression analysis of factors for vitamin D deficiency
From: Prevalence of vitamin D deficiency in the pregnant women: an observational study in Shanghai, China
Predictors | P-value | Odds ratio | 95% confidence interval |
|---|---|---|---|
Season | |||
 Spring | – | 1.000 | Reference |
 Summer | 0.451 | 1.026 | 0.960–1.096 |
 Autumn | < 0.001 | 0.841 | 0.786–0.899 |
 Winter | < 0.001 | 0.607 | 0.566–0.652 |
Categorical age | |||
 18–24 | – | 1.000 | Reference |
 25–29 | < 0.001 | 0.673 | 0.564–0.803 |
 30–35 | < 0.001 | 0.577 | 0.484–0.688 |
  > 35 | < 0.001 | 0.550 | 0.456–0.664 |
Year | |||
 2014 | – | 1.000 | Reference |
 2015 | < 0.001 | 1.186 | 1.101–1.277 |
 2016 | < 0.001 | 1.224 | 1.139–1.316 |
 2017 | < 0.001 | 0.554 | 0.517–0.594 |