PF4 and COVID-19: Vitamin D can decrease oxidative stress in endothelial cells, leading to a decrease in the production of blood clots.[10–13] Understanding the correlation between vitamin D status and specific antibodies like anti-PF4 is crucial in the context of COVID-19.[10,11] While several studies have examined the role of vitamin D and anti-PF4 in COVID-19, none have specifically analyzed the relationship between the 2.