Moderate exposure to sunlight protects against lung cancer, concluded Cedric Garland and colleagues at the University of California at San Diego (US).

The researchers compared the five factors (lung cancer rates, latitude/annual hours of sunlight, annual cloud cover, smoking rates, air pollution levels) in 111 countries worldwide

• The strongest link was, not surprisingly, between smoking and lung cancer rates
• After adjusting for smoking rates:
  
  • the countries with the highest average annual sunshine rates had significantly lower lung cancer rates
  • in women, cancer rates increased as air pollution increased
  • these effects were not attributed to sunlight per se but to vitamin D production in the body triggered by skin and eye exposure to sunlight

Cedric hypothesises that adequate levels of vitamin D cause the body to release chemicals that combine with calcium, causing the cells in lung linings to stick more closely together, reducing their susceptibility to attack from cancer cells. Organ lining cells are known to be the most vulnerable to cancer.

View Vitamin Research Products' vitamin D3 1,000iu supplement