RecruitingPhase 2Drug trialSelenium Supplementation in Moderate-Severely Active Ulcerative Colitis Patients Treated With Advanced TherapiesMicronutrient deficiencies are common in ulcerative colitis (UC). Selenium deficiency is associated with worse disease outcomes including disease flares and need for surgery. Previous in vitro and in vivo studies demonstrated that selenium regulates colonic inflammation, and that selenium supplementation protects against DSS-induced colitis. In this proof-of-concept clinical trial, we aim to test the hypothesis that selenium supplementation in moderate to severely active UC patients will improve responsiveness to advanced therapy such as biologics and small molecules.