Excessive sun increases cancer all around the body
Previous extensive sun exposure and subsequent vitamin D production in patients with basal cell carcinoma of the skin,
has no protective effect on internal cancers.
Bernt Lindelöf, Britta Krynitz, Shiva Ayoubi, Christoph Martschin, Desiree Wiegleb-Edström and Kerstin Wiklund
Eur J Cancer () (2011) DOI: 10.1016/j.ejca.2011.06.049; PMID: 21788128
BACKGROUND: It has been suggested that sunlight through production of vitamin D might have a protective effect on a number of internal cancers. Consequently, in spite of the well known skin cancer risks, some researchers advocate more exposure to ultraviolet radiation, supported by the solarium industry. We estimated the risk of internal cancer before the patient contracted a basal cell carcinoma (BCC) of the skin, the most common cancer in white populations and strongly associated with extensive sun exposure.
METHODS: A nested case control study was undertaken in the whole Swedish population. 115,016 patients with BCC and 987,893 controls were linked to population based registers.
FINDINGS: The cases had an increased risk of getting another form of cancer before the BCC diagnosis: odds ratio (OR)=1.84; 95% confidence interval (CI) 1.81-1.86. This risk was mainly due to skin cancer: OR=4.95; 95% CI 4.81-5.09 but also non-skin cancer risk was elevated: OR=1.37; 95% CI 1.35-1.39. We adjusted the estimates for age, level of income, occupational status in national censuses, place of living and sex, where appropriate. Of the cancers specifically suggested to be related to vitamin D status: colon, prostate, breast, and ovary cancer, all had slightly increased ORs whilst for pancreatic and gastric cancer no increased OR was found.
INTERPRETATION: Patients with BCC, a proxy for extensive sun exposure , run an increased risk of other forms of cancer prior to the diagnosis of BCC. The findings in this study contradict that vitamin D production through extensive sun exposure has any protective effect on internal cancer but emphasise the increased risk for skin cancer.
Copyright © 2011 Elsevier Ltd. All rights reserved.
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People having “extensive” sun (probably with many sunburns over many years) increased their chance of getting cancers many places in the body.
”Extensive” sun increased chance of skin cancer 5X, and increased other cancers by 40%
See also VitaminDWiki
Overview Suntans and melanoma many good charts
Most sunscreens actually increase the growth of skin cancer - May 2010
China has documented that less UV results in more cancer – June 2010
Perhaps 28-40 ng of vitamin D would be good for Melanoma patients – Feb 2011
Sunlight alone does not cause skin cancer - July 2010 Natural News - 13 bullet points and linked video
Subsequent melanomas associated with Bsml gene variation of VDR– May 2011
If avoiding sun for medical reasons you need oral vitamin D – April 2011
Shade is better than sunscreen – does not eliminate the vitamin D – June 2011