Vitamin D3 deficiency 5 times increases risk of having severe COVID-19. Vitamin K2 and Magnesium should be supplemented together with Vitamin D3, in order to prevent long-term health-risk and improve immunoregulatory effects based on a causal loop diagram, disclosed in Simon Goddek, “Vitamin D3 and K2 and their potential contribution to reducing the COVID-19 mortality rate,” International Journal of Infectious Diseases, 99 (2020) 286-290, https://doi.org/10.1016/j.ijid.2020.07.080, JIF 12.073 (top 14% journals in Infectious Diseases).
Menatetrenone, a vitamin K2 analogue, plays an important role in the production of blood coagulation factors. Menatetrenone has also be shown to have antineoplastic effects against several cancer cell lines including hepatocellular carcinoma (HCC) cells. Vitamin K2 inhibits the growth of HCC cells via suppression of cyclin D1 expression through the IKK/InB/NF-nB pathway, according to Iwata Ozaki et al., “Menatetrenone, a Vitamin K2 Analogue, Inhibits Hepatocellular Carcinoma Cell Growth by Suppressing Cyclin D1 Expression through Inhibition of Nuclear Factor KB Activation,” Clinical Cancer Research 2007;13(7) April 1, 2007, https://doi.org/10.1158/1078-0432.CCR-06-2308, JIF 13.801 (top 7% journals in Oncology / top 12% journals in Oncology in 2007).
Animal and human studies suggest that optimal concentrations of both vitamin D and vitamin K are beneficial for bone and cardiovascular health as supported by genetic, molecular, cellular, and human studies, according to Adriana J. van Ballegooijen et al., “The Synergistic Interplay between Vitamins D and K for Bone and Cardiovascular Health: A Narrative Review,” International Journal of Endocrinology, Volume 2017, Article ID 7454376, 12 pages, https://doi.org/10.1155/2017/7454376, JIF 2.803 (top 77% journals in Endocrinology & Metabolism).