From http://www.ewg.org/2010sunscreen/full-report/getting-enough-vitamin-d/
( 2000X more Disability Life Adjusted Year with UV than without UV)
According to a 2006 World Health Organization (WHO) report, Solar Ultraviolet Radiation: Global Burden of Disease from Solar Ultraviolet Radiation, it is important to focus on reducing the disease burden due to both excessive and insufficient UV exposure (WHO 2006). Using the disability-adjusted life year (DALY) as a metric, WHO experts estimated that excessive sun exposure caused the loss of approximately 1.5 million DALYs (0.1 percent of the total global burden of disease) and 60,000 premature deaths in the year 2000, with the greatest burden from UV-induced cortical cataracts and cutaneous malignant melanoma (WHO 2006).
By comparison, the same group of scientists noted that a much larger annual disease burden of 3.3 billion DALYs worldwide would result from very low levels of UV radiation exposure due to disorders of the musculoskeletal system such as rickets and osteoporosis and possibly an increased risk of various autoimmune diseases and life-threatening cancers (Lucas 2008).
Researchers concluded that “without high dietary (or supplemental) intake of vitamin D, some sun exposure is essential to avoid diseases of vitamin D insufficiency” (Lucas 2008).