By Marc Sorenson, EdD, Sunlight Institute…
A study from China demonstrates that residents who have the lowest sun exposure also have the highest risk of death. The study obtained overall death rates and incidence rates from cancers per se from a national database during the years from 1998 to 2002) They compared those death rates to the quantity of sun intensity in the areas (263 counties) in which the residents lived.
The results were telling: Overall death risk for all cancers combined, and specifically for cancers of the esophagus, stomach, colon, rectum, liver, lung, breast and bladder were inversely correlated with increasing sun exposure. Lung cancer showed the greatest protection provided by sun exposure, with a 12% decrease in death risk for every 10 mW/(nm m2) increase in UVB irradiance (a measure of intensity of sun exposure).
Incidence rates of several cancers were also inversely correlated to sun exposure, namely cancers of the esophagus, stomach, colon, rectum and cervix. Only nasopharyngeal cancer and cervical cancer increased with sun exposure. The authors suggested the possibility that vitamin D provided the mechanism by which the overall cancer rates were reduced.
Dr. William Grant has confirmed that there are many cancers that correlate to low sun exposure and/or low vitamin D levels, and there are dozens more diseases beyond cancer that have an inverse relationship with sun exposure. Dr. Grant and I will soon release a book that will delve into all of the diseases that sun exposure helps to prevent. Please world, let us back in the sun without making us feel guilty!
 Chen W, Clements M, Rahman B, Zhang S, Qiao Y, Armstrong BK. Relationship between cancer mortality/incidence and ambient ultraviolet B irradiance in China. Cancer Causes Control. 2010 Oct;21(10):1701-9.
 William B. Grant. Role of solar UVB irradiance and smoking in cancer as inferred from cancer incidence rates by occupation in Nordic countries. Dermato-Endocrinology 4:2, 203–211; April/May/June 2012.