- https://www.news-medical.net/news/20221115/Vitamin-D-can-reduce-severity...
- https://www.nature.com/articles/s41598-022-24053-4 (reference paper)
Overall, the study findings showed vitamin D2 and vitamin D3 supplementation significantly reduced risk of COVID-19 infection and death within 30 days. Therefore, the researchers believe vitamin D3 supplementation could be a valuable strategy for limiting the spread of COVID-19 infection and related death and racial differences in COVID-19 outcomes.
From Nature reference article:
A second recent study in Israel (n = 253 patients with pre-infection vitamin D levels) found a 14-fold increase of severe or critical COVID-19 disease in patients with vitamin D deficiency (< 20 ng/ml) relative to patients with normal vitamin D levels (> = 40 ng/ml), adjusted for age, sex, BMI and comorbidities22.
(important note: Outcomes achieved were only with a minimum increase in D status > 20 ng/ml. Imagine if they tested with cohorts at the 60-100 ng/ml blood level as is recommended for optimum D status - not to mention adding K2 to the mix instead of just the bare minimum of 40 ng/ml. Vitamin D is required to activate T-cells - both attacking T-cells and the ones which calm inflammation (T-helper cells).