From Experience Life, June 2009
Recent studies in North America and Europe indicate that a staggering 95 percent of people are vitamin D deficient — not surprising given how much time we spend inside.
Sunlight doesn’t just help set your internal clock, it actually nourishes your body by helping it create vitamin D. Classified as a water-soluble vitamin, vitamin D acts more like a hormone, working with the parathyroid hormone to balance calcium in the blood and build strong bones. It also maintains healthy cellular growth and regulates the immune system, which prevents excessive inflammation that can lead to autoimmune diseases like rheumatoid arthritis, diabetes, periodontal disease, multiple sclerosis and irritable-bowel diseases.
The Institute of Medicine of the National Academies currently calls for 200 international units (IU) of vitamin D per day for people younger than 50, 400 IU for those 51 to 70, and 600 IU for people 71 and older. But organizations like the American Medical Association and the American Academy of Pediatrics have called on the government to raise those numbers to between 1,000 to 2,000 IU daily.
Read more about sunlight and vitamin D here http://www.experiencelifemag.com/issues/june-2009/health-wellness/light-rhythms.html?ht