“Vitamin D-Binding Protein and Vitamin D Status of Black Americans and White Americans,” by Camille E. Powe, Michele K. Evans, Julia Wenger, Alan B. Zonderman,Anders H. Berg, Michael Nalls, Hector Tamez, Dongsheng Zhang, Ishir Bhan, S. Ananth Karumanchi, Neil R. Powe, and Ravi Thadhani (Vol. 369, No. 21, November 21, 2013, p. 1991-2000).
www.nejm.org/doi/full/10.1056/NEJMoa1306357?query=TOC#t=abstract
