Table 4. Odds ratio (OR) and its 95% Confidence Interval (95%CI) for allergic symptom development with the interaction term between vitamin D deficiency and pollen exposure.

	OR	95% CI			P value
Vitamin D deficiency a	1.05	0.99	–	1.11	.125
Pollen b	1.09	1.06	–	1.12	< .001
Interaction term	1.05	1.00	–	1.11	.059

Those who were seropositive for IgE to JCP and went outdoors on the day were included in the analysis.

Adjusted by desert dust (log-transformed and standardized), humidity, lowest temperature of the day, temperature difference within the day, IgE to house dust mite, family income, smoking status, age, and BMI before pregnancy.

IgE class to house dust mite was treated as ordered categorical.

Age was categorized into 6 groups by 5 years, and was treated as categorical.

BMI before pregnancy was categorized into 3 groups, and was treated as categorical.

Family income was categorized into 6 groups and was treated as ordered categorical.

^a Vitamin D deficiency was defined as serum 25(OH)D level < 20 ng/mL on serum samples taken within 3 months before the symptom response.

^b Pollen count was log-transformed and standardized.