TORONTO, Ont – A new research paper has shed light on the benefits of moderate non-burning sun exposure and calls for an immediate revision of current public health sun directives. It found the public has been misled and not fully informed of the health consequences if they avoid sun exposure. The authors concluded “that non-burning UV exposure is a health benefit and – in moderation – should be recommended as such.”
The commentary, prepared by internationally recognized experts, was published in the International Journal of Environmental Research and Public Health in December. UV radiation is the primary source of vitamin D for people and has been associated with lower disease rates for serious diseases such as some specific cancers, multiple sclerosis, diabetes, cardiovascular disease, Alzheimer’s disease, osteoporosis and age related macular degeneration.
The paper pointed out that the public is confused regarding sun exposure. Messaging to avoid “over exposure” is not clearly defined. What is “over exposure?” In addition, the current sun guidelines are clearly aimed at the northern European Caucasians portion of the population and may not apply for darker skinned populations whose skin can naturally absorb greater sun exposure and who are usually more vitamin D deficient.
The authors examined the current state of scientific research and found that severe sunburns are linked to an increase risk of melanoma but non-burning sun exposure is linked to a reduced risk of melanoma. “This is a message the public never receive from current public health guidelines,” states Dr. David Hoel, lead author, Department of Public Health Sciences, Medical University of South Carolina. “The public is led to believe that all sun exposure should be avoided and that the avoidance of sun exposure is free of risk from a health perspective. That is not the case.”
The paper recommended that public health sun exposure directives advising against “over exposure” should be changed to specifically advising against sun burn for each individuals skin type. This would address the needs for the complete spectrum of the population. The paper stated: “If all sunburns are avoided, these levels can probably be achieved without any appreciable increase in the risk of melanoma and without significant increase in the risk of SCC or BCC.”
In Canada, our vitamin D levels are dropping drastically as more Canadians follow the current public health sun directives and either avoid sun exposure or use sunscreens when outside. Vitamin D deficiency is clearly a sunlight deficiency. Statistics Canada reports that vitamin D levels in Canada have dropped by 13% in the last 6 years. Today, 38% of Canadians do not meet the low level of vitamin D recommended by Health Canada for bone health of 50 nmol/L (20 ng/mL) and 93% are below the vitamin D recommendations from an international expert panel of vitamin D scientists for optimal disease prevention of between 100-150 nmol/L (40-60 ng/mL).
The paper reported that approximately 12% of U.S. deaths per year may be linked to inadequate sun exposure. And that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking.
“Vitamin D supplementation is not always an adequate substitute for sun exposure,” Dr. Frank de Gruijl, co-author, Department of Dermatology, Leiden University Medical Center, The Netherlands explains. “Sun exposure produces more than just vitamin D in your skin. It also produces nitric oxide, dopamine, beta-endorphin, cis-urocanic acid and various immune-active substances with effects throughout the body. A surprising recent finding is that the cis-urocanic acid present in the blood generates glutamate in the brain which enhances learning in mice. In addition, your immune system adjusts to work properly when you are exposed to the sun, and research shows that this can reduce your risk of developing autoimmune diseases such as multiple sclerosis.”
The authors recommend the following new public health directive regarding sun exposure and human health:
“All persons in the world regardless of skin color or latitude of residence, other than those with extraordinary sensitivity to sunlight, should get enough sun exposure to maintain a serum 25(OH)D level well over 20 ng/mL or 50 nmol/L (desirably at 30-60 ng/mL or 75-150 nmol/L) while taking care to avoid sunburn.”
About the Vitamin D Society:
The Vitamin D Society is a Canadian non-profit group organized to increase awareness of the many health conditions strongly linked to vitamin D deficiency; encourage people to be proactive in protecting their health and have their vitamin D levels tested annually; and help fund valuable vitamin D research. The Vitamin D Society recommends people achieve and maintain optimal 25(OH)D blood levels between 100 – 150 nmol/L (Can) or 40-60 ng/ml (USA).