Vitamin D and skin physiology: a D-lightful story. (NIH)
"Throughout evolution, exposure to sunlight and the photosynthesis of vitamin D(3) in the skin has been critically important for the evolution of land vertebrates. During exposure to sunlight, the solar UVB photons with energies 290-315 nm are absorbed by 7-dehydrocholesterol in the skin and converted to previtamin D(3). "
Does Milk Really Contain Vitamin D? (SF Gate)
"Vitamin D is a fat-soluble vitamin, which means your body can store it in the liver and fat cells, that promotes the absorption of calcium, aids in neuromuscular function and supports the immune system. Failing to meet your daily needs affects the strength of your bones, a condition known as rickets in children and osteomalacia in adults."
Lack of Vitamin D May Have Killed Mozart (Discovery News)
"In his high-latitude home in Austria, Mozart was probably running low on the sunshine vitamin for half the year. That deficiency may have put the musician at risk for many of the illnesses he suffered from."