"To reduce the risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40-60 ng/mL (100-150 nmol/L)."
Grant WB, Lahore H,
McDonnell SL, et al. Evidence that Vitamin D Supplementation Could
Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. 2020;12(4):E988. Published 2020 Apr 2. doi:10.3390/nu12040988
McDonnell SL, et al. Evidence that Vitamin D Supplementation Could
Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. 2020;12(4):E988. Published 2020 Apr 2. doi:10.3390/nu12040988