Cancer Doctor
Cancer Doctor

Sunlight, Vitamin D, Cancer

In this video, William B. Grant spends about 15 minutes speaking on "Sunlight, Vitamin D, Cancer" at the 34th Annual Cancer Convention held on Labor Day weekend by the Cancer Control Society.

About William B. Grant

WILLIAM B. GRANT, Ph.D. has a Ph.D. in physics from the University of California, Berkeley (1971). He had a post doc position involving lasers at the Freie Universität Berlin (1971-73). He had a 30-year career in atmospheric sciences with an emphasis on developing and using laser radar (lidar) systems for remote sensing of atmospheric with positions at SRI International (1973-79), the Jet Propulsion Laboratory/California Institute of Technology (1979-89) and NASA Langley Research Center, Hampton, Virginia (1989-2004). In the position with NASA, he participated in many international airborne field expeditions to study the atmosphere, using a lidar system to measure the vertical profile of aerosols and ozone along the flight path.

While living in Virginia, he undertook a project with the Sierra Club to understand the roles of air pollution in reducing the health of the eastern U.S. oaks and hickories. During that project, he learned how to do ecological studies in which populations are defined geographically and both health outcomes and risk-modifying factors are averaged for each population unit, followed by statistical regression analysis.

He turned to health research in 1996, using the ecological approach to link dietary factors to risk of Alzheimer’s disease, resulting in the first paper linking diet to risk of Alzheimer’s disease (Grant, 1997). His next study, also an ecological study, found that while animal fat was an important risk factor for coronary heart disease for men, added sugar (sweeteners) was for women (Grant, 1998).

In 1999, he obtained a copy of the Atlas of Cancer Mortality in the United States, 1950-94 (NIH Publication No. 99-4564) and noticed that for many types of cancer, mortality rates were much higher in the northeast than in the southwest. Building on the work of the brothers Cedric and Frank Garland, he used NASA satellite data for solar UVB doses in July 1992 in ecological studies to show that 13 types of cancer (eight more than previously identified) had mortality rates inversely correlated with UVB doses (Grant, 2002).

After retirement from NASA in 2004, he moved to San Francisco and formed the nonprofit organization Sunlight, Nutrition and Health Research Center ( He has published several additional ecological studies related to UVB on cancers, autism, and dental caries, and several ecological studies on diet and Alzheimer’s disease, cancers, and rheumatoid arthritis. He has also carefully examined how observational studies and randomized clinical trials are conducted regarding vitamin D, resulting in several publications pointing out limitations of such studies and how they can be improved. He also writes reviews and letters to the editor and reviews many manuscripts each year. He works closely with several vitamin D-advocacy organizations.

He has about 360 health publications listed at, of which 260 are related to vitamin D, with 90 of these also on ultraviolet radiation and human health, and 43 on diet and disease. His works have been cited over 20,000 times according to

Email [email protected], website


It's my pleasure to be here today and to help to be able to give you some of the information I've been developing over the past six years. OK, the outline is missing, but I'm going to be discussing the data that support the understanding that ultraviolet B radiation and vitamin D can greatly reduce the risk of developing cancer or increasing the survival once one develops cancer. The ultraviolet B vitamin D cancer hypothesis began around 1980 when the brother Cedric and Frank Garlan looked at a map of the colon cancer mortality rates in United States and saw that the death rates in the south west were much lower than in the northeast. And they hypothesize that sunlight through production of vitamin D was was the main factor. Now. Course, with the Cancer Control Society, John Ott is associated with Cancer Control Society. He actually looked at cancer development in rats and found that in the absence of ultraviolet radiation, they developed more cancer and died more rapidly. But he didn't get quite get around to the vitamin D component of that. What you can see on this map is that the red areas in the Northeast have mortality rates for males around 20 to 30 deaths per hundred thousand per year, whereas in the southwest, it's around as low as 10 desperate or a thousand per year. The contours, the the black contours indicate the amount of sunlight. And you see there's also factor to difference in sunlight in the two regions.

I've now the easiest way to show that vitamin D. That Ultraviolet B plays a role in reducing risk of cancer. Is to do a ecologic study where one takes the cancer mortality rates and looks at the mortality rate with respect to the amount of ultraviolet B radiation hitting those areas. I did that night in 2002 and identified well, at that time he was already known that breast, colon, ovarian and prostate cancer were considered vitamin D sensitive cancers. And I looked at the maps like were just shown there and figured out that there are another 10 types of cancer that were vitamin D sensitive. The critics said, well, there are other factors that contribute to cancer risk as well. And you should include those in the studies in addition. So I added smoking, alcohol consumption, urban rural residents, poverty, Hispanic heritage and confirmed the earlier findings and identified several more vitamin D sensitive cancers. Here's an example of of the different cancers got in the upper left hand is is breast cancer is very similar to the colon cancer, except that in California there are some hot spots. For example, Marin

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