Background: Anemia has a dramatic impact on patient's quality of life, yet anemia in patients with UC is still underdiagnosed and undertreated. Hepcidin has been identified to be a central regulator of iron absorption from the intestines and of plasma iron levels. In this study we evaluated the effect of vitamin D supplementation on haemoglobin levels, patient assessed disease activity and endoscopic assessment in ulcerative colitis (UC). Methods: In this prospective, open-labeled, parallel-group, randomized, comparative clinical study, we assigned newly diagnosed cases of UC with haemoglobin levels between 8-11 gm/dL to receive either standard therapy for 12 weeks or to receive oral 4000IU vitamin D3 along with standard therapy for 12 weeks. Results: Data from 60 patients were analyzed after 12 weeks. Supplementation with vitamin D3 significantly raised haemoglobin level in treatment group from (9.09±0.20) (Mean ± SEM) at baseline to 9.62±0.22 (Mean ± SEM) at 12 weeks. On assessment of abdominal pain with NRS scale at the end of treatment at 12 weeks the reduction in NRS score was to 3.47±0.29 in group I and to 2.23±0.21 in group II (p=0.0012) which was highly significant. There was also a statistically significant reduction in the Likert scale at the end of 4, 8 and 12 weeks in both groups. At week 12, there was no statistical difference between the two groups in improving the endoscopy score. Conclusions: Daily high dose vitamin D supplementation is beneficial in ameliorating UC symptoms like abdominal pain and has a positive effect on haemoglobin levels.