International Journal of Preventive Medicine (Int J Prev Med)2008-780256201402017969EN20140201<p dir="ltr"><strong>Backgrounds: </strong>Vitamin D deficiency is a public health concern even in sunny areas, so we decided to assess the prevalence of vitamin D deficiency and its related factors among university students in Shiraz.</p><p dir="ltr"><strong>Methods: </strong>This cross‑sectional study was carried out on 254 (128 male and 126 female) university students. Demographic questionnaires and a questionnaire on exposure to sun light and sun protection were completed by the participants. Serum 25OH‑vitamin D was measured using a radioimmunoassay kit. Data analysis was done using Statistical Package for Social Sciences (SPSS) software # 16. A <em>P </em>value less than 0.05 was considered as significant.</p><p dir="ltr"><strong>Results: </strong>Mean &plusmn; standard deviation (SD) of serum 25OH‑vitamin D was 49.29 &plusmn; 12.87 (nmol/l) and 27.46 &plusmn; 10.37 (nmol/l) among male and female students, respectively. 51.2% of female students were vitamin D insufficient and 44% of them had vitamin D deficiency. Prevalence of vitamin D insufficiency and marginal status among male students were 49.5 and 48%, respectively. Serum vitamin D of female students was significantly less than the males (<em>P </em>&lt; 0.001). Serum vitamin D was negatively correlated to sun protection score (<em>P </em>&lt; 0.001, r = 0.50), but there was no correlation between serum vitamin D and sun exposure.</p><p dir="ltr"><strong>Conclusions: </strong>Vitamin D deficiency especially among female students is alarmingly prevalent. Increasing use of sunscreen lotion and clothing style could be the main factors inhibiting endogenous vitamin D synthesis which results in its deficiency.</p><p dir="ltr"><strong>Keywords: </strong>Sun protection, university students, vitamin D status</p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/1303http://ijpm.mui.ac.ir/index.php/ijpm/article/download/1303/1611