Vitamin D - The Sun Vitamin
Most populations are becoming Vitamin D deficient as modern society gradually move from outdoors into shelters. Hitherto, Vitamin D was thought to be responsible for only bone health. The current scientific understanding is it's much more. It affects immunity, cancers, inflammation, mental health, diabetes and many more.
I try to get one hour of full-body sun exposure daily.http://www.bbc.com/news/health-33757929