This study evaluated ulceroprotective and antioxidant effect of 1,25 dihydroxyvitamin D3 against gastric damage in rats. Rats were treated intraperitoneally with either 1,25 dihydroxyvitamin D3 (0.25 mu g/kg) or saline for 14 days. On day-15, the non-selective cyclooxygenase inhibitor indomethacin (10 mg/kg; subcutaneously), the inhibitor of sulfhydryl groups N-ethylmaleimide (10 mg/kg; intraperitoneally) or ATP-sensitive K+ channel blocker glibenclamide (10 mg/kg; orally) was given prior to 1,25 dihydroxyvitamin D3. Animals were euthanized at 60 min post ulcerogenic challenge (0.3 M HCl and 60% ethanol (0.2 mL; orally). Stomach and blood were collected for biochemical and histological evaluations. HCl/Ethanol group revealed severely damaged mucous and glandular epithelium with diffuse hemorrhage and inflammatory cell infiltration (microscopic score: 10.67 +/- 0.67 and ulcer index: 33.13 +/- 5.09). 1,25 dihydroxyvitamin D3 decreased the extent of damage (microscopic score: 6.80 +/- 0.02 and ulcer index: 19.00 +/- 4.34; p < 0.05), and the elevations in gastric malondialdehyde level (p < 0.001), myeloperoxidase activity (p < 0.001), nuclear factor-kappa B expression (p < 0.05), and apoptotic index (p < 0.05) following HCl/Ethanol challenge. Decreased gastric glutathione following HCl/Ethanol administration was restored by 1,25 dihydroxyvitamin D3 (p < 0.01). These findings demonstrated protection of the gastric mucosa against HCl/Ethanol-induced injury by 1,25 dihydroxyvitamin D3 via attenuation of inflammatory reaction, oxidative stress and apoptosis.