Over the past several years, medical science seems to be developing a trend toward greater valuation of the benefits of UV-B in vitamin D production, and the value of UV radiation for vitamin D regulation has moderated the prevailing philosophy of major public health agencies around the world that reducing sun exposure as much as possible should be the public health goal. For example, in 2004 the internet site for the Cancer Council of Australia (2004) stated: "Deliberate exposure to sunlight does not provide any health benefits. Australians receive more than sufficient sunlight for vitamin D production from just sitting near a window or by as little as two minutes outside during the day." Because transmission of UV-B through glass is negligible (Turnbull et al., 2005), sitting near a window is probably not a significant source of vitamin D, and the two-minute exposure is generally shorter than needed for vitamin D synthesis (Webb and Engelsen, 2005). In March 2005, many health agencies in Australia issued a joint statement that confirmed the hazards of UV radiation for skin cancer, but they also recognized some of the benefits of moderate exposure for vitamin D production (Australian and New Zealand Bone and Mineral Society et al., 2005), and the internet site for the Cancer Council of Australia (http://www.cancer.org.au/home.htm, updated October 2007) now endorses that view in a page on "The Risks and Benefits of Sun Exposure".
In the U.S., public information generally originates from the U.S. CDC (2005) and the U.S. Environmental Protection Agency (U.S. EPA, 2005). A major study on the effectiveness of educational interventions to reduce skin cancer by reducing exposure to solar radiation was published by the CDC (Saraiya et al., 2004). Seeking shade, including tree shade, was prominently mentioned for UV protection in that study, although the subtleties of different UV exposures possible in "shade" were not discussed. The CDC recently re-evaluated the vitamin D issue (Dr. Mona Saraiya, pers. comm., June 27, 2005). It would seem that many of the findings of the study on intervention effectiveness could be translated to the slightly different messages that would be needed if moderate sun exposure for vitamin D photosynthesis were adopted as a goal.
A question arises as to the appropriate education for non-white populations regarding sun exposure. Recommendations for sun exposure are sometimes given by skin type (Cancer Research UK, 2008), although more often the recommendations are for everyone to avoid the sun as much as possible (U.S. CDC, 2005; U.S.
EPA, 2005) without a differentiation of the message on the basis of skin color. This is despite the high percentage of vitamin D deficiency among African-Americans (Giovannucci, 2005). However, recommendations do differ in other countries from those in the U.S. For example, there are no education programs in Japan on reducing sun exposure, even for school children (Ono et al., 2005); which might be anticipated because of the low incidence of skin cancer among Asians.
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Complete Guide to Preventing Skin Cancer. We all know enough to fear the name, just as we do the words tumor and malignant. But apart from that, most of us know very little at all about cancer, especially skin cancer in itself. If I were to ask you to tell me about skin cancer right now, what would you say? Apart from the fact that its a cancer on the skin, that is.