Effect of sex, pubertal stage, body mass index, oral contraceptive use, and C-reactive protein on vitamin D binding protein reference values - von Heimburg, Philipp; Baber, Ronny; Willenberg, Anja; Wölfle, Philip; Kratzsch, Jürgen; Kiess, Wieland; Vogel, Mandy (Frontiers in Endocrinology, 2025)