Vitamin D for COVID-19 Treatment Vitamin D • Strengthens innate and adaptive immune systems • Restores gap junctions, tight junctions, and adherent junctions to maintain integrity of epithelial barrier • Increases production of cathelicidin in epithelial cells of respiratory tract which disrupt bacterial membranes by electrostatic interactions • Prevents cytokine storm which is the underlying cause of ARDS in COVID-19 Interestingly, the death rate and occurrence of ARDS among COVID-19 patients increases with latitude. Increase in latitude indicates low sun exposure and thus low vitamin D levels. Studies suggest the role of vitamin D in strengthening immune system in COVID-19 patients and combating ARDS. Currently, there is insufficient data to support the urgent use of vitamin D in COVID-19 patients.