AUTHOR=Xie Zhongjian , Wang Xiangbing , Bikle Daniel D. TITLE=Editorial: Vitamin D Binding Protein, Total and Free Vitamin D Levels in Different Physiological and Pathophysiological Conditions JOURNAL=Frontiers in Endocrinology VOLUME=11 YEAR=2020 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.00040 DOI=10.3389/fendo.2020.00040 ISSN=1664-2392