What are the best nutrients for asthma ?

There is now  extensive literature on  relationship between diet and respiratory disease.

In asthma, observational studies have shown encouraging evidence of  protective effect of several nutrients on disease prevalence and symptoms, including 

1. vitamin C,
2. vitamin E,
3. selenium ,
4. magnesium.

They’re  good source of antioxidants such as beta carotene and vitamins C and E, which may help reduce lung swelling and irritation (inflammation) caused by cell-damaging chemicals known as free radicals.