Outdoor workers have less melanoma than indoor workers who receive up to 9 times less UV
Indoor workers get three to nine times less solar UV (290–400 nm) exposure than outdoor workers get, yet only indoor workers have an increasing incidence of Melanoma. Increased intermittent UVA exposures and inadequately maintained cutaneous levels of vitamin D3 promotes melanoma. (1)
A review of published studies found that a significant number of Australians and New Zealanders have less than optimal serum vitamin D levels, with mild to moderate deficiency ranging from 33 to 84% depending on age, skin colour and/or those in residential care.
These studies have also reported a significant relationship between low vitamin D status and an increase in the prevalence of diseases including; diabetes, CVD, metabolic syndrome, osteoporosis, hypertension, certain cancers, several autoimmune diseases the Flu and all-cause mortality. The data also suggest that normalising blood 25(OH)VitD levels by supplementation with vitamin D3 may have a positive effect in disease prevention. Is this increased UV exposure in the Southern Hemisphere and the resulting skin sun damage more detrimental to overall health than vitamin D deficiency?
There is evidence that excessive sun exposure increases the risk of skin damage, ageing and skin cancers. Excessive exposure to sunlight causing sunburn at any time in life increases a person's risk of developing skin cancer. However, people who experience intermittent exposure to high levels of UV radiation such as tanning on the beach on the weekend, appear to be at greater risk while those who experience continual exposure to lower levels even if the total dose of UV radiation is the same, have the lowest incidence of melanoma. That is, non-burning regular sun exposure such as obtained in the early morning and later in the afternoon seems to have a protective effect against skin cancer(2). And, a moderate amount of unblocked sunlight may actually be beneficial to most people, and could reduce the risk of many other diseases – including, paradoxically, melanoma itself. (3)
Another example of this paradox is research from the University Of California School Of Medicine. This study found that higher incidence of melanoma occurred among Navy desk workers than among sailors who worked outdoors(4).
Also, a study (Nürnberg B, et al. 2008) from the Department of Dermatology, The Saarland University Hospital, Homburg, Germany that examined the progression of malignant melanoma reported. Basal 25-hydroxyvitamin D levels were lower in melanoma patients as compared to the control group. And progression of malignant melanoma was associated with significantly reduced 25(OH)vit D serum levels. Their findings add to the growing body of evidence that 25(OH)vit D serum levels may be of importance for pathogenesis and progression of malignant melanoma(5)
1. Med Hypotheses. 2009 Apr;72(4):434-43. doi: 10.1016/j.mehy.2008.09.056. Epub 2009 Jan 19.
2. Article, Prevention & Early Detection, Memorial Sloan-Kettering Cancer Centre 2008.
3. Setright R, The Use Of Nutritional And Herbal Supplements In The Maintenance Of Prostate Health
The Setright Letter, 2012 June, 02:12:1-15
4. Garland FC. et al. Occupational sunlight exposure and melanoma in the U.S. Navy. Arch Environ Health. 1990 Sep-Oct;45(5):261-7
5. Nürnberg B, et al. Progression of malignant melanoma is associated with reduced 25-hydroxyvitamin D serum levels.Exp Dermatol. 2008 Jul;17(7):627
The information given by Naturopath Russell Setright in this article is for general educational purposes only and not for the diagnosis and treatment of any disease or condition. Always see your Healthcare Practitioner for any suspected disease accident or condition and follow there expert advice.