BackgroundPostoperative peritoneal adhesions are major complications of abdomino-pelvic surgeries. We aim to investigate the preventive and therapeutic effects of cholecalciferol (vitamin D3) supplementation on postoperative peritoneal adhesion (PPA) in a rat model. Materials and methodsThis randomized, controlled, single blinded animal study was performed in university laboratory. Thirty-two female Wistar albino rats were randomly separated into four equal groups as, group 1: (21-d vitamin-D treatment group), group 2: (21-d corn oil group), group 3: (14-d vitamin-D treatment group), and group 4: (control group). Uterine horns were traumatized with bipolar cautery for adhesion formation process. On postoperative day 14, all the animals were sacrificed and evaluated for adhesions. Adhesion extent, severity, degree, and total adhesion scores were evaluated macroscopically. Histopathologically, adhesions were evaluated for inflammation, fibrosis, and NFκB (nuclear factor kappa b) staining. ResultsOn postoperative day 14, we found lesser peritoneal adhesion severity, degree, extent, and total adhesion scores with vitamin-D administration compared with control and corn oil-treated groups; the difference was statistically significant (P < 0.001). Histopathologic adhesion scores of inflammation and fibrosis were statistically different among the four groups (P < 0.001). NFκB staining was markedly increased in control and vehicle groups. The NFκB staining scores were statistically different between the groups (P < 0.001). The intensity of NFκB staining was lower in both vitamin 14 and 21-d vitamin-D groups. ConclusionsVitamin D as a supplement and as a therapeutic medicine decreases the formation of PPA in an animal model. In future studies, the association of vitamin D deficiency and PPA should be studied. In addition, vitamin D should be investigated in future clinical studies for the prevention of PPAs.