prevalence of vitamin d deficiency and its related factors among university students in shiraz, iran

backgrounds: 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. methods: 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 p value less than 0.05 was considered as significant. results: mean ± standard deviation (sd) of serum 25oh‑vitamin d was 49.29 ± 12.87 (nmol/l) and 27.46 ± 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 ( p < 0.001). serum vitamin d was negatively correlated to sun protection score ( p < 0.001, r = 0.50), but there was no correlation between serum vitamin d and sun exposure. conclusions: 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.