From the National Cancer Institute:
Vitamin D & Cancer Prevention

From Harvard School of Public Health:
Vitamin D and Health

Medical study published in The New York Times:
Low Vitamin Levels Linked to disease in TWO studies

And here is a link to ALL you could possibly want to know about how Vitamin D
works, and the recommended daily dosage (2000 IU) for adults. This data, presented by the
Linus Pauling Institute of Oregon State University is excellent. Not the "bullshit" presented
by "CBS This Morning" on March 17, 2015.

All about Vitamin D