Figure 2.

Serum 25-hydroxyvitamin D level and perceived stress status according to sex. Perceived stress status in daily life was assessed using the following question in the self-reported questionnaire: “During usual life activities, how much do you feel stressed?”; 1 = almost no stress, 2 = a little stress, 3 = much stress, 4 = very much stress (high and low stress groups were defined as those with scores of 3 or 4 and 1 or 2, respectively). Data are presented as estimated means (%). p-values were obtained by Pearson’s chi-squared using a complex sample design.