Very informational article on Vitamin D in January (2008) issue of Scientific American.
Key Concepts:
Vitamin D, long associated only with its role in bone formation, is actually active throughout the human body, powerfully influencing immune system responses and cell defenses.
It can be obtained from food or manufactured by human skin exposed to sunlight. Measures of vitamin D levels show, however, that many people have too little of it circulating in their blood to protect health.
Clear associations between low vitamin D levels and cancers, autoimmunity, infectious diseases and other conditions suggest that current daily intake recommendations for this critical nutrient need revision.
