Background and Objective: 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.

Methods: 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.

Results: There was a significant difference between the two groups regarding “weight for age Z-score”, however, no significant difference was found between them with respect to “height for age Z-score” 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).

Conclusion: 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.