Abstract: Compositions, methods of manufacturing compositions, methods of protecting against respiratory problems including coronavirus and coronavirus-associated severe acute respiratory syndrome (SARS) in humans and animals, are provided. Compositions comprising inorganic nitrate used for improving nitric oxide levels, improving health and/or reducing symptoms of SARS are provided. The compositions and methods are applicable for subjects experiencing SARS, and for protecting non-infected subjects against SARS. Compositions and methods for improving nitric oxide levels in a subject disclosed herein comprise administration of compositions comprising inorganic nitrate such as potassium nitrate or sodium nitrate optionally combined with ascorbate.