Vitamin D3 and K2 and their potential contribution to reducing the COVID-19 mortality rate
A system analysis published in the International Journal of Infectious Diseases in 2020 evaluated the metabolic pathways behind vitamins D3 and K2's immunomodulating effect by elaborating a causal loop diagram. The study's primary goal is to advise which dietary supplements are significant for COVID-19 patients to decrease the morbidity rates. The analysis highlighted that vitamin D serum levels above 35 ng/mL are correlated with the mortality rate of COVID-19 patients. The majority of the Western population is deficient in Vitamin D, and Vitamin D3 supplementation also requires additional vitamin K2 intake. Finally, the research called attention to the immunoregulating function of vitamin D that could decrease the global epidemic mortality. Vitamin D3 supplement increases anti-inflammatory and immunoregulating interleukin 10 (IL-10) cytokines and decreases inflammatory effects in the host. On the other hand, regular intake of vitamin D3 can cause hypercalcemia, which is the buildup of calcium in the blood leading to vascular calcification, osteoporosis, and kidney stones. However, it is known that the reason for hypercalcemia is mainly associated with vitamin K2 deficiency. Vitamin K2 activates osteocalcin protein which deposits calcium in the bones; however, non-activated osteocalcin inhibits calcium absorption. Therefore, the promotion of osteocalcin synthesis rate requires vitamin K2 as a natural antagonist.