Table 3.

Multivariate linear regression analyses of serum 25OHD levels

	Coefficient	95% CI	p Value
Age	−0.52	−0.65 to –0.40	<0.0001
Sex
Male	Reference		<0.0001
Female	−1.40	−1.88 to 0.91
Region of residence
Urban	−0.85	−1.55 to 0.14	0.0189
Rural	Reference
BMI	−0.10	−0.17 to 0.03	0.0034
Smoking
Active	0.47	−0.42 to 1.36	0.3017
Passive	−0.04	−0.62 to 0.53	0.8842
No	Reference
Season
April−October	Reference		<0.0001
November−March	−3.38	−3.97 to 2.79

Statistics were carried out using multivariable linear regression.

Model: adjusted for age, sex, region, BMI, smoking, season.

25OHD, 25-hydroxyvitamin D; BMI, body mass index.