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Response to CDC: Calling for reduction in sun exposure discrepent to health equity goals

Posted on: August 31, 2013   by  [email protected]


I want to share with you my response to the CDC’s request for comments on its policy related to UV exposure. My comment would not have been possible without information I first learned about right here on the Vitamin D Council website. Many of the studies I cite here I know about only because of my Vitamin D Council membership.

Comment on anticipated Office of the Surgeon General statement on the public health problem of skin cancer.

AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health and Human Services (HHS).


FROM: Tom Weishaar, Program in Health Education, Department of Health and Behavior Studies, Teachers College, Columbia University

HHS/CDC and the Office of the Surgeon General are interested in receiving information on the following topics: (1) Barriers to reducing UV exposure from the sun and from indoor tanning devices…

The primary barrier to a public health policy of reducing UV exposure is that it ignores the overall impact of UV exposure on human health.

Creating public health policy based solely on the relationship between UV exposure and skin cancer while ignoring all of the other relationships between UV exposure and human health is ill-advised. Moreover, as I will show, it is in opposition to one of the four overarching goals of HHS/CDC as stated in Healthy People 2020 [1], to achieve health equity, eliminate disparities, and improve the health of all groups.

To begin, let’s look at the bigger picture of UV exposure and human health. Since 1934 anthropologists have been discussing, and in recent years have accepted, the theory that human skin color is an evolutionary adaptation to UV exposure [2-7].

They note that our evolutionary ancestors had dark skin that was protective against the high UV levels found near the equator. However, as human population groups moved away from the equator and its intense UV radiation, skin tones in those groups gradually became lighter because individuals with lighter skin had the evolutionary advantage of better health.

The primary mechanisms through which UV impacts health are skin damage leading to skin cancer and the production of vitamin D in the skin. There are additional mechanisms that we know about [8] and there may be others that are still unknown to us.

In humans, light skin requires less exposure to UV to synthesize the same amount of vitamin D as darker skin. The primary source of vitamin D in humans is synthesis in the skin as a result of UV exposure. The only food source with significant amounts of vitamin D is wild ocean fish. Because of these factors, at the latitude of the United States there are vitamin D disparities related to skin color. Moreover, many of the same diseases and health conditions are associated with both inadequate vitamin D status and with health disparities [9-11].

From a public health perspective, the theory of the evolution of human skin color implies that there will be health disparities in any population with diverse skin colors. In low UV areas, including parts of the U.S., those with dark skin will be relatively less healthy because of a lack of UV exposure, while in high UV areas, including parts of Australia, those with light skin will be relatively less healthy because of overexposure to UV. It is the work of public health professionals to solve both of these problems, not to pick one at the expense of the other.

Using data from NHANES, my colleague Joyce Vergili and I have recently demonstrated that vitamin D status is a biological determinant of health disparities [12]. Our study replicated earlier findings using health care costs as the dependent variable [13]. When you ask Americans to rate their health, on average, non-Hispanic blacks and Mexican-Americans both rate their health worse than non-Hispanic whites. A discrepancy remains even after controlling for socioeconomic status and other reasonable covariates. However, when you additionally control for vitamin D status, the difference in how blacks and whites rate their health disappears and the difference between the ratings of Mexican-Americans and whites is greatly reduced.

While our study was not a randomized controlled trial, other researchers have already demonstrated causal relationships between vitamin D status and specific diseases and conditions [14-16]. Our study, while epidemiological, is similar to studies that have been used in the past to set health policy, for example, on the health effects of smoking. Our study demonstrates that it will not be possible for public health authorities to eliminate health disparities without eliminating the skin-color based disparities in vitamin D nutriture.

While HHS/CDC has repeatedly stated that one of its overarching goals is to eliminate health disparities, a policy to reduce UV exposure in Americans will have exactly the opposite effect – it will increase health disparities. It is particularly inequitable to broadly recommend reduction of UV exposure to Americans when, according to the American Cancer Society, Melanoma is rare among African Americans; the lifetime risk of developing melanoma is 23 times higher among whites than among African Americans (page 21). [17]

A recent study from Australia highlights the difficulties of a public health policy to reduce UV exposure [18]. The study targeted dark-skinned women who had moved to Australia as humanitarian refugees from Horn of Africa countries – mostly Somalia – and mostly within the last five (none more than ten) years. One participant said, When we were in our countries, we were exposed to the sun a lot. Our sun is very healthy. We don’t have cancer in the skin…[but here in Australia]…there are some rays in the sun. Skin cancer, so sometimes we compare, we say is it better to have lack of vitamin D or to have skin cancer? You compare the both, which one is safer. We think vitamin D [deficiency] is safer (p. 295).

While it is not too late to adjust a statement from the Surgeon General to make it equitable to all groups, the HHS/CDC and other health policy expert panels currently support health inequities through a double standard for evidence regarding UV’s health impacts.

When the policy concerns improving the health of those with light skin, there is no requirement for evidence from randomized controlled trials. All of the available scientific evidence that UV has a negative impact on health is epidemiological. For example, in the discussion section of the U.S. Preventative Services Task Force supporting article on screening for skin cancer, the task force reports:

The literature on screening for skin cancer has several limitations. A major limitation is the lack of direct evidence linking skin cancer screening to improved health outcomes. An adequately powered, population-based RCT of screening demonstrating mortality outcomes would require approximately 800,000 participants because of the relatively low melanoma-related mortality rate in the United States. [19]

To fully understand this statement, it helps to realize that in the U.S., deaths related to skin cancer represent only 2% of all deaths related to cancer [17].

On the other hand, when the policy concerns improving the health of those with dark skin by increasing vitamin D levels, epidemiological evidence is not considered adequate – only randomized controlled trials will do. This was the policy when the Institute of Medicine raised the recommended daily allowance of vitamin D in 2011 [16] and it is the policy that the U.S. Preventative Services Task Force uses when examining issues related to the health effects of vitamin D deficiency [20].

This double standard is inequitable, harms the health of vulnerable groups, and is not a worthy foundation for U.S. public health policy.

In its RCT-based nutritional recommendation regarding vitamin D, the IOM recommended that, for bone health, 20 ng/mL is the optimal population level of the marker used to determine vitamin D status – serum 25-hydroxyvitamin D or 25(OH)D. While the average 25(OH)D levels for the U.S. as a whole are above that level, the average for non-Hispanic blacks in the U.S. in 2003-2006 (the most recent data available) was 15.0 ng/mL [12]. Meanwhile, the mean level for traditionally-living people in equatorial Africa is 46 ng/mL [21].

The background for the IOM’s RCT-based recommendation was the classic understanding of vitamin D – that vitamin D is activated in the kidney and passed into the blood stream as a hormone to control blood calcium levels. In this understanding vitamin D has an endocrine function – it is created at one place in the body and is used to send signals to cells in other parts of the body. In the classic understanding, vitamin D impacts bone health and nothing more [16].

There is also a modern understanding of vitamin D, which the IOM acknowledged by noting it has possible roles in carcinogenesis, cardiovascular disease, diabetes, falls, immune response, neuropsychological functions, physical performance, and preeclampsia. The modern understanding includes this endocrine signaling, but also acknowledges that vitamin D is activated inside many other cells, where it is used to signal the DNA machinery inside that cell (autocrine signaling) or inside adjacent cells (paracrine signaling) to up- or down-regulate genes that code for specific proteins [16, 22]. The IOM said that optimal vitamin D levels for these other functions of vitamin D were unknown, however, many other experts, who – like skin cancer researchers – review epidemiological and biological studies as well as RCTs, disagree with this assessment [15, 23].

Continuing the current public health policy of reducing UV exposure without attending to the effects of that policy on people of color is inequitable and borders on public health malpractice. Moreover, HSS/CDC must put an end to the double standard for evidence regarding UV’s impact on health. At an absolute minimum, an equitable policy regarding UV exposure must include policies and targeted behavior change programs to increase the mean serum 25(OH)D level of U.S. subpopulations with darker skin colors above the IOM recommended level of 20 ng/mL.


  1. U.S. Department of Health and Human Services Healthy People 2020. 2010.
  2. Chaplin, G. and N.G. Jablonski, Vitamin D and the Evolution of Human Depigmentation. Am J Phys Anthropol, 2009. 139(4): p. 451-461.
  3. Jablonski, N.G., The evolution of human skin and skin color. Annu Rev Anthropol, 2004. 33: p. 585-623.
  4. Jablonski, N.G. and G. Chaplin, The evolution of human skin coloration. Journal of Human Evolution, 2000. 39(1): p. 57-106.
  5. Loomis, W.F., Skin-pigment regulation of vitamin-D biosynthesis in man. Science, 1967. 157(3788): p. 501-&.
  6. Murray, F.G., Pigmentation, sunlight, and nutritional disease. American Anthropologist, 1934. 36(3): p. 438-445.
  7. Yuen, A.W.C. and N.G. Jablonski, Vitamin D: In the evolution of human skin colour. Med Hypotheses, 2010. 74(1): p. 39-44.
  8. Juzeniene, A. and J. Moan, Beneficial effects of UV radiation other than via vitamin D production. Dermatoendocrinol, 2012. 4(2): p. 109-17.
  9. Bibuld, D., Health Disparities and Vitamin D. Clinical Reviews in Bone and Mineral Metabolism, 2009. 7(1): p. 63-76.
  10. Grant, W.B. and A.N. Peiris, Possible Role of Serum 25-Hydroxyvitamin D in Black-White Health Disparities in the United States. Journal of the American Medical Directors Association, 2010. 11(9): p. 617-628.
  11. Harris, S.S., Vitamin D and African Americans. Journal of Nutrition, 2006. 136(4): p. 1126-1129.
  12. Weishaar, T. and J.M. Vergili, Vitamin D status is a biological determinant of health disparities. J Acad Nutr Diet, 2013. 113(5): p. 643-51.
  13. Peiris, A.N., B.A. Bailey, and T. Manning, The Relationship of Vitamin D Deficiency to Health Care Costs in Veterans. Military Medicine, 2008. 173(12): p. 1214-1218.
  14. Holick, M.F., Vitamin D deficiency. N Engl J Med, 2007. 357(3): p. 266-281.
  15. Holick, M.F., et al., Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab, 2011. 96(7): p. 1911-30.
  16. Ross, A.C., et al., Dietary Reference Intakes for Calcium and Vitamin D. 2011, Washington, DC: National Academies Press.
  17. American Cancer Society, Cancer Facts and Figures 2013. 2013.
  18. Pirrone, A., et al., Vitamin D deficiency awareness among African migrant women residing in high-rise public housing in Melbourne, Australia: a qualitative study. Asia Pac J Clin Nutr, 2013. 22(2): p. 292-9.
  19. U.S. Preventative Services Task Force. Screening for Skin Cancer – Research Gaps. 2009; Available from: http://www.uspreventiveservicestaskforce.org/uspstf09/skincancer/skincanart.htm.
  20. U.S. Preventative Services Task Force. Final Research Plan – Screening for Vitamin D Deficiency. 2013; Available from: http://www.uspreventiveservicestaskforce.org/uspstf13/vitddefic/vitddeficfinalresplan.htm.
  21. Luxwolda, M.F., et al., Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. British Journal of Nutrition, 2012. 108(9): p. 1557-1561.
  22. Morris, H.A. and P.H. Anderson, Autocrine and paracrine actions of vitamin D. The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists, 2010. 31(4): p. 129-38.
  23. Hollis, B.W. and C.L. Wagner, Vitamin D requirements and supplementation during pregnancy. Current Opinion in Endocrinology Diabetes and Obesity, 2011. 18(6): p. 371-375.

4 Responses to Response to CDC: Calling for reduction in sun exposure discrepent to health equity goals

  1. Rita and Misty


    I enjoyed your above comment very much, and you raised a legitimate point regarding the racial inequity of the CDC’s current proposal on UV’s health impacts.

    Tom, there are many various points to consider regarding sun exposure, and this is precisely why I find the dilemma to be so important.

    I think we all agree that sunshine is needed for so much more than just vitamin D production. Yet, sun exposure, particularly intermittent and/or sunburn, has been implicated with both non-life- threatening and life-threatening skin cancers. To further complicate the matter, consistent sun exposure, and the production of cutaneous vitamin D have shown to be both preventative and curative with respect to melanoma. Add to this mix the growing body of evidence that sun exposure plays an important role in preventing at least 12 various internal cancers as well as autoimmune diseases like MS and Lupus, and it feels like we are in a Catch-22 situation.

    But are we?
    Is there an Occam’s Razor we are missing?

    Are we standing so close to the problem that we cannot focus on the solution?

    Perhaps we must simply readjust our focus.

    Is it plausible that an optimal 25(OH)D level protects the body from any damage of sun exposure, while also allowing the body to better utilize sunshine for other sun-dependent pathways, such as melatonin and serotonin production?

    Would that be why consistent sun exposure has shown to be healthy? Is it because consistent sun exposure raises the body’s 25(OH)D level to optimal?

    I will share with you that when my 25(OH)D level was raised to 74 ng/ml, I stopped burning when exposed to high noon sun. I now can sit outside, with most of my skin exposed, from 10 a.m. to 2 p.m. under full summer sun and I do not burn. In fact, I barely tan. I am redheaded, with skin level 2. I must state that I live in Connecticut, so the sun exposure I receive isn’t extremely strong, even in summer. But, I used to burn. Now, I do not.

    The vitamin D blood serum level of 74 ng/ml is much higher than the IOM’s sufficiency level of 20 ng/ml.

    So of course, this will beg the question: “Just what is an optimal 25(OH)D level?”

    Again, the IOM has ruled on 20 ng/ml as being sufficient.

    Yet, current studies of present day hunter/gatherer societies report a vitamin D blood serum level of approximately 50 ng/ml as being natural. This is 2X the level of the average urbanite. And, many city dwellers have vitamin D blood serum levels of lower than 25 ng/ml–especially those of darker skin pigmentation.

    I think that there will be no successful resolution of the sun exposure matter until we revisit and correct the IOMs ruling of 20 ng/ml as being a sufficient vitamin D blood serum level. It is way too low.

    How can we attempt to conclude the benefits (or detriments) of sun exposure, without knowing what the effects of sun exposure would be under optimal bodily conditions? In other words, under an optimal 25(OH)D level—50 ng/ml—80 ng/ml.

    Unfortunately, the IOMs ruling won’t be changed overnight, over days, or even over months—it is going to take years. And, it won’t change at all if leaders in the Vitamin D Community become tired, defeated or disenchanted, and decide to walk away from their life mission.

    So, what about the CDCs well intentioned but misguided attempt to protect the public from high levels of UV exposure? I think that although Dr. Campbell does have a valid point with respect to reducing dangerous levels of UV exposure from the sun and from indoor tanning devices, especially for those individuals who are “intermittent” sun worshippers, he presents his point in an unbalanced message.

    I hope that Dr. Campbell would reconsider his stance to include a healthier message: one which incorporates appropriate sunning protocols, designated by skin levels, to accommodate the production of cutaneous synthesis of vitamin D, as well as a compensatory plan to improve vitamin D sufficiency to at least 20 ng/ml within the general population through oral supplementation and/or food fortification.

    In my opinion, Dr. Campbell’s document contains serious flaws by his neglecting to consider the following points:

    1. The role of sun exposure as necessary for production of cutaneous synthesis of vitamin D;
    2. The evidence that cutaneous vitamin D has both a preventive and possibly curative effect with respect to melanoma;
    3. That optimal vitamin D blood serum levels play important roles in reducing risk of bone disease, autoimmune diseases, type 2 diabetes, heart disease, many types of cancers and infectious diseases;
    4. That there is currently a vitamin D pandemic;
    5. That his recommendations do not consider a compensatory vitamin D plan through oral supplementation and/or food fortification.

    If accepted as presented, Dr. Campbell’s recommendations will ensure that that vitamin D deficiency continues to be the #1 public health issue of this century.

    We in the Vitamin D Community are also at fault here regarding ensuring that vitamin D deficiency continues to be the #1 public health issue of the century if we don’t circle around and hit the IOM again. We must work together to raise the 25(OH)D sufficiency level to AT LEAST 40 ng/ml.

    Those who know better have responsibility to do more.

    In my opinion and my 2 cents worth.

    Be well,

  2. Rita and Misty

    : ) VDC-I love the graphics, but doesn’t the sun rise in the EAST? The sun and the plane are both in the wrong direction (imho) 😉

  3. Tom Weishaar

    Hi Rita – just to clarify, the IOM said 20 ng/mL was a sufficient level for bone health. It said it didn’t know the sufficient level for the other aspects of vitamin D and left it at that. As I said in my comment, that’s because the IOM only looked at randomized controlled trials. If that was the standard for UV reduction, the game would be over, because there aren’t any RCTs related to UV and skin cancer. This double-standard for evidence is, in my opinion, the point at which we need to apply continuous pressure. – Tom

  4. Rita and Misty

    Hey Tom, Thank you for emphasizing the point regarding 20 ng/ml as sufficient for bone health.

    Here is the interesting thing I bump up against: Many health professionals I talk with actually think that 20 ng/ml is sufficient ENOUGH, and they do not make the distinction that you just emphasized–that the IOM said it didn’t know the sufficiency level for the other aspects of vitamin D.

    I have had physicians tell me that 60 ng/ml is way too high of a 25(OH)D level; and that 20 ng/ml is just fine.

    So IMO they:

    a. Think that vitamin D is only for bone health;
    b. Don’t realize that the IOM said it did not know the sufficiency level for other aspects of vitamin D

    Either way, we in the Vitamin D Community still have MUCH work to do regarding outreach.

    Be well, and thank you!

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