Free and Bioavailable 25-Hydroxyvitamin D Concentrations are Associated With Disease Activity in Pediatric Patients With Newly Diagnosed Treatment Naïve Ulcerative Colitis. Issue 3 (16th February 2018) - Sauer, Cary G; Loop, Matthew S; Venkateswaran, Suresh; Tangpricha, Vin; Ziegler, Thomas R; Dhawan, Ashish; McCall, Courtney; Bonkowski, Erin; Mack, David R; Boyle, Brendan; Griffiths, Anne M; Leleiko, Neal S; et al.