en پژوهشي اصیل Original Research <p><strong>Background and Objective</strong><strong>:</strong> Vitamin D (Vit D) has an important role as immunoregulator. Its deficiency is deemed as a risk factor for respiratory system infection. In this study the serum Vit D levels of healthy and with pneumonia children were compared.</p> <p><strong>Methods</strong><strong>:&nbsp;</strong>In this prospective case control study, 31 hospitalized children due to pneumonia and 40 healthy children both aged between 6 and 60 months were included. Serum Vit D level in these two groups were measured and compared. P values less than 0.05 considered significant.</p> <p><strong>Results</strong><strong>:&nbsp;</strong>There was a significant difference between the two groups regarding &ldquo;weight for age Z-score&rdquo;, however, no significant difference was found between them with respect to &ldquo;height for age Z-score&rdquo; as well as serum Vit D level. The mean serum Vit D level was 30.71 ng/ml and 31.89 ng/ml in case group and control group, respectively (P=0.77).</p> <p><strong>Conclusion:&nbsp;</strong>Our study did not support a straight relation between serum Vit D level and pneumonia. This finding might be due to consumption of supplemental Vit D by most of infants and toddlers in Iran. Further investigation in this area is recommended.</p> Pneumonia, Children, Vitamin D 8 10 http://ijca.iums.ac.ir/browse.php?a_code=A-10-1-27&slc_lang=en&sid=1 Nasrin Hoseiny–Nejad nasrnejad@gmail.com 1003194753284600161 1003194753284600161 Yes Zohreh Kalbasi z_kalbassi@yahoo.com 1003194753284600162 1003194753284600162 No Shirin Sayyahfar sayyahfar.sh@iums.ac.ir 1003194753284600163 1003194753284600163 No