biostudies-literatureSauer CGNational Center for Advancing Translational SciencesNCATS NIH HHSNIDDK NIH HHSNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of Health641-650https://www.ebi.ac.uk/biostudies/studies/S-EPMC6176888biostudies-literatureUnknown24(3)<h4>Background</h4>Vitamin D regulates intestinal epithelial and immune functions, and vitamin D receptor deficiency increases the severity of murine colitis. Bioavailable 25-hydroxyvitamin D (25(OH)D) is available to target tissues and may be a driver of immune function. The aim is to evaluate the relationship of bioavailable 25(OH)D to the clinical expression of treatment naive pediatric ulcerative colitis (UC).<h4>Methods</h4>The PROTECT (Predicting Response to Standardized Pediatric Colitis Therapy) study enrolled children ≤17 years newly diagnosed with UC. Free and total 25(OH)D were directly measured and 25(OH)D fractions were compared with disease activity measures.<h4>Results</h4>Data were available on 388 subjects, mean age 12.7 years, 49% female, 84% with extensive/pancolitis. ThInflammatory bowel diseasesFree and Bioavailable 25-Hydroxyvitamin D Concentrations are Associated With Disease Activity in Pediatric Patients With Newly Diagnosed Treatment Naive Ulcerative Colitis.PMC6176888UL1TR000454T32 DK007727UL1 TR002378UL1 TR000454P30 DK0783925U01DK095745Walters TDavis SWang JDenson LAMarquis AKugathasan SBaldassano RNSpada KLLoop MSHyams JSPatel SBonkowski EGriffiths AMVenkateswaran SBaker SSRosh JBoyle BKeljo DJLeleiko NSDhawan ATangpricha VMarkowitz JMcCall CSauer CGMack DRZiegler TRfalseFree and Bioavailable 25-Hydroxyvitamin D Concentrations are Associated With Disease Activity in Pediatric Patients With Newly Diagnosed Treatment Naive Ulcerative Colitis.<h4>Background</h4>Vitamin D regulates intestinal epithelial and immune functions, and vitamin D receptor deficiency increases the severity of murine colitis. Bioavailable 25-hydroxyvitamin D (25(OH)D) is available to target tissues and may be a driver of immune function. The aim is to evaluate the relationship of bioavailable 25(OH)D to the clinical expression of treatment naive pediatric ulcerative colitis (UC).<h4>Methods</h4>The PROTECT (Predicting Response to Standardized Pediatric Colitis Therapy) study enrolled children ≤17 years newly diagnosed with UC. Free and total 25(OH)D were directly measured and 25(OH)D fractions were compared with disease activity measures.<h4>Results</h4>Data were available on 388 subjects, mean age 12.7 years, 49% female, 84% with extensive/pancolitis. Th2018-01-01T00:00:00Z2018 Feb2025-04-18T16:10:35.49Z2019-08-04T07:59:27ZS-EPMC61768882946238410.1093/ibd/izx052