Abstract: medRxiv preprint doi: https://doi.org/10.1101/2020.04.24.20075838; this version posted April 28, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. Vitamin D insufficiency is prevalent in severe COVID-19 Frank H. Lau, MD, FACS1, Rinku Majumder, PhD2, Radbeh Torabi, MD1, Fouad Saeg, BS3, Ryan Hoffman, BS4, Jeffrey D. Cirillo, PhD5, Patrick Greiffenstein, MD, FACS1 Affiliations: 1. Department of Surgery, Louisiana State University Health Sciences Center New Orleans (LSUHSC-NO) 2. Department of Biochemistry, LSUHSC-NO 3. Tulane School of Medicine 4. LSUHSC-NO School of Medicine 5. Department of Microbial Pathogenesis and Immunology, Texas A&M College of Medicine Corresponding Author: Dr. Frank H. Lau, MD, FACS; Department of Surgery, Louisiana State University Health Sciences Center New Orleans, 1542 Tulane Ave, 7th Floor, New Orleans, LA 70112; email: flau@lsuhsc.edu; phone: (504) 412-1240 NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. medRxiv preprint doi: https://doi.org/10.1101/2020.04.24.20075838; this version posted April 28, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission.