Background: The objective of this extension phase of the quasi-experimental GERIA-COVID study was to determine whether vitamin D3 supplementation taken prior to or during COVID-19 was associated with better 3-month survival in geriatric patients hospitalized for COVID-19.
Methods: Intervention group was defined as all participants supplemented with vitamin D3 prior to or during COVID-19 (n = 67). Supplements were either bolus vitamin D3 (ie, 50,000 IU per month, or 80,000 IU or 100,000 IU or 200,000 IU every 2-3 months), or daily supplementation with 800 IU.