In its November 2007 issue, a leading science magazine ran an in-depth, seven-page article entitled “Cell Defenses and the Sunshine Vitamin,” summarizing that scientists now recognize that Vitamin D does much more than build strong bones and that many people are dangerously deficient.
Two scientists working at McGill University in Canada, reporting on their research and the research of other scientists, state in Scientific American that Vitamin D may have many uses in the human body besides building strong bones.

According to the scientists, Luz E. Tavera-Mendoza and John H. White, Vitamin D intake may also be beneficial in the prevention of cancer, multiple sclerosis, diabetes, and fighting tuberculosis, influenza and inflammatory bowel disease. The researchers say that there is an emerging “widespread consensus” among experts that a large part of the population has levels of Vitamin D in their bodies that is well below optimal concentrations for health, particularly in temperate regions, due to decreased sunlight and or less time outdoors, and during or just after the winter months. One study indicated that as many as 92 percent of adolescent girls in Northern Europe may have deficient levels of Vitamin D and 37 percent have severely deficient levels.
The problem is far worse among African-Americans than Americans with lighter skin. Almost half of African-American women may be seriously Vitamin D deficient, with presumably still another fraction deficient. Furthermore, the authors say researchers at Harvard University and elsewhere believe the FDA minimum recommended daily allowance of Vitamin D is far too low. The Recommended Dietary Allowance (RDA) ranges from 200 to 600 International Units (IU). In fact, the authors themselves take Vitamin D supplements. The first author takes 1000 IU during wintertime and the second author takes 5,000 IU in wintertime.
Similar research has also been recently performed by researchers at the Queensland University of Technology who found that many elderly were likely not getting sufficient Vitamin D due in part to insufficient exposure to the sun.
— From Wikinews.com and Scientific American magazine