Sunbeds, vitamin D and health

Thursday November 24, 2011

Sunbeds, vitamin D and health: recent publications and publicity

Two recent publications on vitamin D and UV exposure provide contrasting views on the benefits and risks of sunbeds.

Ultraviolet exposure and women’s health

The first publication, an editorial, identifies the current increasing scientific and public interest into the potential beneficial effects of vitamin D levels in the prevention of a “myriad of diseases”, including cardiovascular disease, type I diabetes and cancer. The authors explore the limitations of studies to date, highlighting the controversy that remains “as to whether UV exposure - most importantly - endogenous vitamin D levels, can be used to prevent major health outcomes besides those related to bone health”. They acknowledge, however, that “there is evidence beyond scientific doubt that adequate endogenous vitamin D levels promote bone health and that UV exposure (and in particular solarium use) damages the skin and increases skin cancer risk”.

The authors state that as diet in many countries may not be sufficient to maintain adequate vitamin D levels, most women will obtain their vitamin D through moderate sun exposure or dietary supplements. With regard to sunbeds as a source of UV exposure, they conclude that as there are proven harms related to them, “there is a case for banning their use altogether” or prohibiting use among minors. In their view, “public education alone, without regulations and policy implementation, is unlikely to change risky behaviour”.

Source:

Weiderpass E and Veierod MB. Ultraviolet exposure and women’s health. Maturitas (2011), doi:10,1016/j.maturitas.2011.07.023.
http://www.maturitas.org/article/S0378-5122%2811%2900271-4/abstract

Vitamin D, sun, sunbeds and health

Another recent article has been publicised by the Indoor Tanning Association of New Zealand (INTANZ) in a media release entitled “New Study Suggests Sunbed Skin Cancer Risk May Be Worth It”. According to INTANZ, the article concludes that “ultraviolet radiation (UVR) from the sun or sunbeds may contribute to skin cancer, but because of its ability to stimulate vitamin D the increase in risk might be a small price to pay”.

The article, to which INTANZ refers, was published online on 24 October 2011 in the journal “Public Health Nutrition”. As outlined in the abstract, the article reports on a literature review using a MEDLINE search of published data on the health effects of solar radiation, sunbeds and vitamin D.

In contrast to the above editorial that highlights the controversy surrounding the evidence of benefit of Vitamin D beyond bone health, the authors of this review article state that “Vitamin D gives many health benefits beyond bone and muscle health”, including decreased risk for cancer, protection against infectious diseases and a range of non-cancerous diseases (diabetes, CVD, multiple sclerosis and mental disorders). With regard to the risk of UV exposure, the authors contend that sun exposure as the main cause of cutaneous malignant melanoma (CMM) in most populations is a matter that is disputed. They conclude that “the overall health benefit of an improved vitamin D status may be more important than the possibly increased CMM risk resulting from carefully increasing UV exposure”.

Commentary sought on this review article from Dr Mary Jane Sneyd, an epidemiologist at the Hugh Adam Cancer Epidemiology Unit at the University of Otago, includes the following:

• The evidence review is not a systematic one.
• The authors present a very biased and selective summary of the science.
• The contention that a link between CMM and sun exposure is disputed is not a fair representation of the body of scientific evidence.
• The cancer benefits are overstated and only reference the authors’ own work. There are high quality systematic reviews and analyses of this research area available.
• The authors overlook recent research on vitamin D toxicity.
• The authors do, in fact, show that sunbed use is associated with increased melanoma risk.

In the view of Associate Professor Brian Cox, Director of the Hugh Adam Cancer Epidemiology Unit, “the article confirms that numerous studies have found an increased risk of melanoma associated with sunbed use, but considerably overemphasises the current speculation that modest vitamin D levels are associated with serious disease”.

Sources:

New Study Suggests Sunbed Skin Cancer Risk May Be Worth It. INTANZ media release
http://www.scoop.co.nz/stories/SC1111/S00010/new-study-suggests-sunbed-skin-cancer-risk-may-be-worth-it.htm

Moan J, Baturaitea1 Z, Juzeniene A, Porojnicua AC. Vitamin D, sun, sunbeds and health. Public Health Nutrition (2011), DOI: 10.1017/S1368980011002801.
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8413712#

Dr Mary Jane Sneyd and Associate Professor Brian Cox, personal communication, November 2011.