From the Abstract: "Results: One population study and seven clinical studies were identified, which reported D3 blood levels preinfection or on the day of hosp

From the Abstract: "Results: One population study and seven clinical studies were identified, which reported D3 blood levels preinfection or on the day of hospital admission. The two independent datasets showed a negative Pearson correlation of D3 levels and mortality risk (r(17) = −0.4154, p = 0.0770/r(13) = −0.4886, p = 0.0646). For the combined data, median (IQR) D3 levels were 23.2 ng/mL (17.4–26.8), and a significant Pearson correlation was observed (r(32) = −0.3989, p = 0.0194). Regression suggested a theoretical point of zero mortality at approximately 50 ng/mL D3. Conclusions: The datasets provide strong evidence that low D3 is a predictor rather than just a side effect of the infection." A review of studies on subjects.