from the Cochrane Review
Among the possible benefits of vitamin D is reducing asthma attacks. There has been growing interest in the role of vitamin D in the management of asthma because it might help reduce upper respiratory infections that can worsen asthma. A review of randomized studies found evidence that taking oral vitamin D supplements in addition to standard asthma medication is likely to reduce severe asthma attacks. The lead author in the Cochrane Review, Professor Adrian Martineau, said this is an exciting result, but said some caution is warranted. He noted that most of the patients in these studies were adults with mild or moderate asthma—very few with severe asthma--and it is not known if the benefit can be seen in all patients or just those who have low levels of vitamin D to start with.