Abstract: nutrients Article Associations between Genetic Variants in the Vitamin D Metabolism Pathway and Severity of COVID-19 among UAE Residents Fatme Al-Anouti 1,† , Mira Mousa 2,3 , Spyridon N. Karras 4 , William B. Grant 5 , Zainab Alhalwachi 3 , Laila Abdel-Wareth 6,7 , Maimunah Uddin 8 , Nawal Alkaabi 8 , Guan K. Tay 3,9,10 , Bassam Mahboub 11 and Habiba AlSafar 3,12, *,† 1 2 3 4 5 6 7



 8 9 Citation: Al-Anouti, F.; Mousa, M.; 10 Karras, S.N.; Grant, W.B.; Alhalwachi, 11 Z.; Abdel-Wareth, L.; Uddin, M.; 12 Alkaabi, N.; Tay, G.K.; Mahboub, B.; et al. Associations between Genetic Variants in the Vitamin D Metabolism * † Department of Health Sciences, College of Natural and Health Sciences, Zayed University, Abu Dhabi, United Arab Emirates; Fatme.AlAnouti@zu.ac.ae Nuffield Department of Women’s and Reproductive Health, Oxford University, Oxford OX1 4BH, UK; mira.mousa@stx.ox.ac.uk Center for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates; zainabhhalwachi@gmail.com (Z.A.); guan.tay@uwa.edu.au (G.K.T.) National Scholarship Foundation, 55535 Thessaloniki, Greece; karraspiros@yahoo.gr Sunlight, Nutrition and Health Research Center, San Francisco, CA 94164-1603, USA; williamgrant08@comcast.net National Reference Laboratory, Abu Dhabi, United Arab Emirates; WarethL@ClevelandClinicAbuDhabi.ae Pathology and Laboratory Medicine Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates Department of Pediatric Infectious Disease, Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates; muddin@seha.ae (M.U.); nalkaabi@seha.ae (N.A.) Psychiatry, Medical School, University of Western Australia, Perth, WA 6009, Australia School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA 6027, Australia Dubai Health Authority, Rashid Hospital, Dubai, United Arab Emirates; bhmahboub@dha.gov.ae Department of Biomedical Engineering, College of Engineering, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates Correspondence: habiba.alsafar@ku.ac.ae Both authors contributed equally to this work. Pathway and Severity of COVID-19 among UAE Residents. Nutrients 2021, 13, 3680. https://doi.org/ 10.3390/nu13113680 Academic Editor: Andrea Fabbri Received: 30 September 2021 Accepted: 15 October 2021 Published: 20 October 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2021 by the authors. Abstract: Vitamin D has many effects on cells in the immune system. Many studies have linked low vitamin D status with severity of COVID-19. Genetic variants involved in vitamin D metabolism have been implicated as potential risk factors for severe COVID-19 outcomes. This study investigated how genetic variations in humans affected the clinical presentation of COVID-19. In total, 646 patients with SARS-CoV-2 infection were divided into two groups: noncritical COVID-19 (n = 453; 70.12%) and a critical group (n = 193; 29.87%). Genotype data on the GC, NADSYN1, VDR, and CYP2R1 genes along with data on serum 25-hydroxyvitamin D levels were compiled in patients admitted to a major hospital in the United Arab Emirates between April 2020 and January 2021. We identified 12 single-nucleotide polymorphisms associated with the critical COVID-19 condition: rs59241277, rs113574864, rs182901986, rs60349934, and rs113876500; rs4944076, rs4944997, rs4944998, rs4944979, and..