BACKGROUND
Previous studies in pediatric populations have demonstrated that vitamin D deficiency is common in patients with large burns. The aim of the current comparative study was to investigate the serum level of vitamin D in patients with large burns [>20% total body surface area (TBSA)] after 6 months of therapy. 
METHODS
This case control study was conducted during 6-month period from 2017 to 2018 in Amiralmomenin Hospital, Shiraz, Iran. Forty two patients with large burns (>20% TBSA) and at least 6 months’ post-burn period were enrolled. Also, 42 healthy and age and sex matched controls from those referring for routine check-ups were included for comparison. None of the patients and controls received vitamin D supplements. The serum level of calcium (Ca), parathormone (PTH) and vitamin D were compared between the groups. 
RESULTS
There was no significant difference between the two study groups regarding the baseline characteristics including the age (p=0.085), gender (p=0.275) and duration of sun exposure (p=0.894). We found that those with major burns had significantly higher serum levels of PTH (50.48±26.49 vs. 33.64±15.80; p=0.001). In addition, the serum levels of vitamin D were significantly lower in burn patients compared to healthy controls (18.15±9.18 vs. 31.43±16.27; p<0.001). 
CONCLUSION
Major burns (≥20% TBSA) are associated with increased serum levels of PTH and decreased serum levels of vitamin D. However, serum levels of calcium are not affected by major burns.