How does vitamin D prevent exacerbation in asthmatic?

An annotated bibliography has to come from peer reviewed medical journals. The articles/journals have to be from 2000-2011. Please let me know if you need anything else. Thank you!

Here are the links that you go to:

http://web.ebscohost.com.pearl.stkate.edu/ehost/results?sid=63022eab-7848-494e-8272-75392ef787cd%40sessionmgr10&vid=3&hid=8&bquery=%28vitamin+AND+D+AND+asthma%29&bdata=JmRiPWNtZWRtJnR5cGU9MCZzaXRlPWVob3N0LWxpdmU%3d

http://scholar.google.com.pearl.stkate.edu/scholar?hl=en&as_sdt=0,24&q=vitamin+d+and+asthma