Abstract: nutrients Article Vitamin D Supplementation Associated to Better Survival in Hospitalized Frail Elderly COVID-19 Patients: The GERIA-COVID Quasi-Experimental Study Gaëlle Annweiler 1,2 , Mathieu Corvaisier 3,4 , Jennifer Gautier 3 , Vincent Dubée 1,5,6 , Erick Legrand 1,7 , Guillaume Sacco 3,8 and Cédric Annweiler 1,3,8,9,10, * on behalf of the GERIA-COVID study group 1 2 3 4 5 6 7 8 9 10 * School of Medicine, Health Faculty, University of Angers, 49045 Angers, France; gaelle.annweiler@gmail.com (G.A.); Vincent.Dubee@chu-angers.fr (V.D.); ErLegrand@chu-angers.fr (E.L.) Department of Medicine, Clinique de l’Anjou, 49044 Angers, France Department of Geriatric Medicine, Research Center on Autonomy and Longevity, University Hospital, 49933 Angers, France; Mathieu.Corvaisier@chu-angers.fr (M.C.); JeGautier@chu-angers.fr (J.G.); yogisacco@gmail.com (G.S.) Department of Pharmacy, Angers University Hospital, 49933 Angers, France Nantes-Angers Cancer and Immunology Research Center (CRCINA), Inserm, University of Angers, 49000 Angers, France Department of Infectious and Tropical Diseases, Angers University Hospital, 49933 Angers, France Department of Rheumatology, Angers University Hospital, 49933 Angers, France EA4638, Laboratory of Psychology of the Pays de la Loire, University of Angers, 49045 Angers, France Gérontopôle of Pays de la Loire, 44000 Nantes, France Robarts Research Institute, Department of Medical Biophysics, Schulich School of Medicine and Dentistry, the University of Western Ontario, London, ON N6A 5K8, Canada Correspondence: Cedric.Annweiler@chu-angers.fr; Tel.: +332-4135-4725; Fax: +332-4135-4894 Received: 23 September 2020; Accepted: 28 October 2020; Published: 2 November 2020



 Abstract: Background. The objective of this quasi-experimental study was to determine whether bolus vitamin D supplementation taken either regularly over the preceding year or after the diagnosis of COVID-19 was effective in improving survival among hospitalized frail elderly COVID-19 patients. Methods. Seventy-seven patients consecutively hospitalized for COVID-19 in a geriatric unit were included. Intervention groups were participants regularly supplemented with vitamin D over the preceding year (Group 1), and those supplemented with vitamin D after COVID-19 diagnosis (Group 2). The comparator group involved participants having received no vitamin D supplements (Group 3). Outcomes were 14-day mortality and highest (worst) score on the ordinal scale for clinical improvement (OSCI) measured during COVID-19 acute phase. Potential confounders were age, gender, functional abilities, undernutrition, cancer, hypertension, cardiomyopathy, glycated hemoglobin, number of acute health issues at admission, hospital use of antibiotics, corticosteroids, and pharmacological treatments of respiratory disorders. Results. The three groups (n = 77; mean ± SD, 88 ± 5 years; 49% women) were similar at baseline (except for woman proportion, p = 0.02), as were the treatments used for COVID-19. In Group 1 (n = 29), 93.1% of COVID-19 participants survived at day 14, compared to 81.2% survivors in Group 2 (n = 16) (p = 0.33) and 68.7% survivors in Group 3 (n = 32) (p = 0.02). While considering Group 3 as reference (hazard ratio (HR) = 1), the fully-adjusted HR for 14-day mortality was HR = 0.07 (p = 0.017) for Group 1 and HR = 0.37 (p = 0.28) for Group 2. Group 1 had longer survival time than Group 3 (log-rank p = 0.015), although there was no..