Will selenium supplements relieve my asthma?

Glutathione peroxidase (GSH-Px) is an enzyme that contains selenium that uses glutathione to help metabolize hydrogen peroxide, thus protecting against oxidative damage. Individuals with asthma tend to have higher oxidative activity, lower levels of selenium, and diminished glutathione peroxidase activity.

There's been just one study on the effects of selenium supplementation on the increased pulmonary oxidative burden in asthmatics, which showed increases in serum and platelet selenium and GSHPx activity. Improvements in subjective symptomatology were also observed. However, objective measurements of lung function showed no change.