Three key points on the relationship between vitamin D3 levels and immunity against viruses:
1. Immune System Regulation: Vitamin D3 helps regulate both innate and adaptive immune responses, enhancing the pathogen-fighting effects of monocytes and macrophages and reducing inflammation.
2. Antiviral Defense Support: Adequate vitamin D3 levels promote the production of antimicrobial peptides like cathelicidins and defensins, which can directly combat viruses and reduce viral replication.
3. Deficiency Linked to Higher Risk: Low vitamin D3 levels have been associated with increased susceptibility to respiratory infections, such as influenza and COVID-19, suggesting that maintaining sufficient levels may help lower the risk or severity of viral infections.