Its interesting that this study is bottom up not finding anything. So 5000 generic vitamin users and one of the ten chronic conditions researched was asthma.

Its interesting that this study is bottom up not finding anything. So 5000 generic vitamin users and one of the ten chronic conditions researched was asthma. Working the opposite direction, https://www.cureus.com/articles/7343-a-review-on-the-role-of-vitamin-d-in-asthma https://www.cureus.com/articles/7343-a-review-on-the-role-of... is a survey paper covering 14 recent observational studies of the effect of Vit D on Asthma and 12 of the studies showed actual improved results for folks with asthma. Its not a numbers game; google and the AAFA imply about 7 percent of adults have asthma related condition, and 7% of 5K would be about 350 people in the study likely had asthma. The survey paper had studies with up to, for example "616 children diagnosed with asthma in Costa Rica" so the numbers are similar. I just find it interesting that if you ask random untrained people how, for example, vit D affects their asthma you get no result, but if a professional scientific study is run there is a statistically significant difference in outcome.