Over and over we see reports on the importance of maintaining higher than government recommended levels of vitamin D
especially to help avoid Covid and other respiratory diseases as well as lower cancer risk.
Overcoming Infections Including COVID-19, by
Maintaining Circulating 25(OH)D Concentrations
Above 50 ng/mL
Study the figures in this article - especially the ones showing risk of Covid death and serum vitamin D levels. The single most important thing you can do to protect your health from inhaled virus' is to test your vitamin D level and RAISE it if it is below 50 ng/ml. Ideally you want your blood plasma vitamin D level to average 70 ng/ml.
I can't stress this enough. Anyone on this forum should know the importance of vitamin D to minimize or outright prevent disease. It boggles my mind why government agency's tasked with healthcare continue to ignore the science and evidence in favor of only pharmaceutical approaches.
Fortunately, there are scientists (authors of the article linked above) who publish so we can learn and apply without relying on government alone.
(* one of the charts in the article shows how high vitamin D down regulates nfKB genetic pathway. NfKB enhancement favors CML expansion. Vitamin D is so important in helping keep CML at bay)