Vitamin K: meta-analysis of COVID-19 studies

All studies   Mortality   ICU   Hospitalization   Serious outcomes   Cases   RCTs   RCT mortality   Peer-reviewed   All outcomes  
0 0.5 1 1.5+ All studies 14% 2 7K Improvement, Studies, Patients Relative Risk Mortality -200% 1 40 ICU admission -200% 1 40 Hospitalization 17% 1 40 Cases 14% 1 7K RCTs -200% 1 40 Prophylaxis 14% 1 7K Late -200% 1 40 Vitamin K for COVID-19 c19early.org December 2025 Favorsvitamin K Favorscontrol
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.13-69.5] death 1/20 0/20 Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Late treatment -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk Deschasaux-Tanguy 14% 0.86 [0.74-0.99] cases 7,766 (all patients) per SD change Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.04 Prophylaxis 14% 0.86 [0.74-0.99] 14% lower risk All studies 14% 0.86 [0.75-1.00] 1/20 0/20 14% lower risk 2 vitamin K COVID-19 studies c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.043 Effect extraction pre-specified(most serious outcome) Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.13-69.5] 1/20 0/20 Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Late treatment -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk All studies -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk 1 vitamin K COVID-19 mortality result c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.34-26.5] 3/20 1/20 Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.33 Late treatment -200% 3.00 [0.34-26.5] 3/20 1/20 200% higher risk All studies -200% 3.00 [0.34-26.5] 3/20 1/20 200% higher risk 1 vitamin K COVID-19 ICU result c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.33 Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) 17% 0.83 [0.49-1.43] hosp. time 20 (n) 20 (n) Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.52 Late treatment 17% 0.83 [0.49-1.43] 20 (n) 20 (n) 17% lower risk All studies 17% 0.83 [0.49-1.43] 20 (n) 20 (n) 17% lower risk 1 vitamin K COVID-19 hospitalization result c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.52 Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.13-69.5] death 1/20 0/20 Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Late treatment -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk All studies -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk 1 vitamin K COVID-19 serious outcome c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Effect extraction pre-specified(most serious outcome) Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ Deschasaux-Tanguy 14% 0.86 [0.74-0.99] cases 7,766 (all patients) per SD change Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.04 Prophylaxis 14% 0.86 [0.74-0.99] 14% lower risk All studies 14% 0.86 [0.74-0.99] 14% lower risk 1 vitamin K COVID-19 case result c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.04 Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.13-69.5] death 1/20 0/20 Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Late treatment -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk All studies -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk 1 vitamin K COVID-19 Randomized Controlled Trial c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Effect extraction pre-specified(most serious outcome) Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.13-69.5] 1/20 0/20 Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Late treatment -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk All studies -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk 1 vitamin K COVID-19 RCT mortality result c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.13-69.5] death 1/20 0/20 Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.5 Late treatment -200% 3.00 [0.13-69.5] 1/20 0/20 200% higher risk Deschasaux-Tanguy 14% 0.86 [0.74-0.99] cases 7,766 (all patients) per SD change Improvement, RR [CI] Treatment Control Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.04 Prophylaxis 14% 0.86 [0.74-0.99] 14% lower risk All studies 14% 0.86 [0.75-1.00] 1/20 0/20 14% lower risk 2 vitamin K COVID-19 peer reviewed studies c19early.org December 2025 Tau​2​ = 0.00, I​2​ = 0.0%, p = 0.043 Effect extraction pre-specified(most serious outcome) Favors vitamin K Favors control 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2+ KOVIT Visser (DB RCT) -200% 3.00 [0.13-69.5] death 1/20 0/20 Improvement, RR [CI] Treatment Control KOVIT Visser (DB RCT) -200% 3.00 [0.34-26.5] ICU 3/20 1/20 KOVIT Visser (DB RCT) 17% 0.83 [0.49-1.43] hosp. time 20 (n) 20 (n) Deschasaux-Tanguy 14% 0.86 [0.74-0.99] cases 7,766 (all patients) per SD change Vitamin K COVID-19 outcomes c19early.org December 2025 Favors vitamin K Favors control