Top Nutrition Researchers Challenge Conventional Wisdom With Recommendation for More Sun Exposure

July 20, 2015, CLEARWATER, FL—Organizations such as the World Health Organization’s International Agency for Research on Cancer, the American Cancer Society, and the Office of the U.S. Surgeon General have all made public calls for reducing ultraviolet (UV) exposure, whether from indoor UV or from the sun.  Such recommendations stem, appropriately, from efforts to reduce cancer. At the same time, the recommendations are accompanied by a brief recognition of the importance of vitamin D, also known as the “sunshine vitamin,” along with suggestions that sufficient amounts of vitamin D can be obtained solely through food and dietary supplements.

Sunshine: Does More Mean Better Health? 
A group of scientific researchers now suggests that these recommendations, which include avoiding sun exposure between the hours of 10 a.m. and 3 p.m., may be less beneficial than originally thought.  In their Commentary, “Sunlight and Vitamin D: Necessary for Public Health,” the authors argue that humans have evolved with physiological adaptations to help protect the skin from the sun and that increased sun exposure, based on latitude, has been shown  to provide protection from several different types of cancer, type 1 diabetes, multiple sclerosis, and other diseases. 

The authors of the Commentary are Carole A. Baggerly, Christine B. French and Sharon L. McDonnell, GrassrootsHealth, Encinitas, CA; Raphael E. Cuomo, Cedric F. Garland, and Edward D. Gorham, Department of Family and Preventive Medicine, University of California-San Diego, La Jolla, CA; William B. Grant, Sunlight, Nutrition and Health Research Center, San Francisco, CA; Robert P. Heaney, Creighton University, Omaha, NE; Michael F. Holick, Department of Medicine, Boston University Medical Center, Boston, MA; Bruce W. Hollis and Carol L. Wagner, Medical University of South Carolina, Charleston, SC; Mary Pittaway, Special Olympics International, Washington, DC; Paul Seaton, Alaska State House of Representatives, Juneau, AK; and Alexander Wunsch, Wismar University of Applied Science, Wismar, Germany. The article appears in the July-August 2015 edition of the Journal of the American College of Nutrition (JACN), the flagship publication of the American College of Nutrition (ACN). The article is available online to the public at no charge at

Challenge to Conventional Wisdom
The authors identify the physiological processes spurred by exposure to the sun which includes elevation of vitamin D status, and other benefits such as the release of nitric oxide in the body which can serve to widen the blood vessels and decrease blood pressure, and the production of beta-endorphin resulting in an increased feeling of well-being, boosting the immune system, aiding wound healing, and advancing the production of melatonin and serotonin, both vital for circadian rhythm control.

The Commentary also provides insight into past studies revealing how sunlight and vitamin D can have an impact on the treatment for various cancers, the risk for type I diabetes, and a wide range of disorders that can be traced to vitamin D deficiencies in pregnant women.  Essentially the authors believe that low vitamin D status does not cause disease or dysfunction as much as such status impairs the body’s cellular response to internal and external signals.  Accordingly, the Commentary authors provide criteria used in determining the appropriate levels of vitamin D which includes the intake necessary for minimizing functional adaptation, the status found in our ancestors, and the amount necessary for critical life functions.

Deficiency in vitamin D has been linked to 19 of the 30 leading causes of death in the United States.  Raising the vitamin D level of the population could result in a reduction of 336,000 deaths of 2.1 million tabulated in 2010.  This and the clear evidence that not all skin cancers can be attributed to moderate sun exposure leads to a new effort to provide new advice and counsel to the public regarding exposure to UV rays.

A Call to Action
The authors propose that the U.S. Surgeon General’s office, the World Health Organization, the Institute of Medicine, and other health entities, together or separately, engage in defining and quantifying the benefits and harms of sun exposure and to develop the measurement methods needed for their detection and quantification.  This should be followed by recommendations for individual exposure that is safe and beneficial.  

The Commentary offers an important call for action, and the vital steps to reverse a course of action, avoiding the sun, that has produced deleterious effects on overall population health.


About the Journal of the American College of Nutrition
The Journal of the American College of Nutrition (JACN) publishes original and innovative research articles, commentaries and other data about nutrition which is useful for researchers, physicians, and other health care professionals. The journal is published six times per year and is the flagship publication of the American College of Nutrition.

NOTE TO EDITORS: The article is available online at no charge at
To schedule an interview with a Commentary author, please contact the American College of Nutrition’s Media Relations Department at

Keywords:  Vitamin D, benefits of sun exposure, benefits of vitamin D, UV rays, Journal of the American College of Nutrition, JACN, American College of Nutrition, public health