Watch this short 5-minute presentation of Dr. Mercola interviewing expert Dr. William Grant, internationally recognized research scientist and vitamin D expert. You'll discover how easily a million cancer deaths could be prevented each year worldwide -- just by the simple use of sunlight. Plus, why MORE of those living at higher, less sunny latitudes die from cancer...Dr. Grant, whose background is in atmospheric sciences, has applied the ecologic approach to the study of dietary and environmental links to chronic disease. He has worked at the level of senior research scientist at such notable institutions as SRI International, the Jet Propulsion Laboratory, and the NASA Langley Research Center.
More recently, Dr. Grant has uncovered exciting potential for the use of vitamin D in the prevention and treatment of a number of high-incidence cancers found in Western populations. He is the director of the Sunlight, Nutrition and Health Research Center (SUNARC), an entity devoted to research, education, and advocacy relating to the prevention of chronic disease through changes in diet and lifestyle.
Dr. Grant has also authored or coauthored over 60 articles in peer-reviewed journals, edited two books of reprints, and contributed half a dozen chapters to other books.
To hear the entire exclusive interview with Dr. Grant, join the Mercola Inner Circle. As we enjoy the remaining late summer days here in the United States, it’s important to realize that you may need to spend more time in the sun to get enough vitamin D. Come September, the sun is lower in the sky for most of the day, which means that a light-skinned person may need longer than 20 minutes in the sun each day, and a dark-skinned person could need one hour to 90 minutes to produce enough vitamin D.
Doing This Could Save Millions of Lives
It seems so simple. Let the sun shine on your skin and just like that you reduce your risk of numerous chronic diseases, including:
- Heart Disease
- Inflammatory Bowel Disease
- Rheumatoid Arthritis
- Multiple Sclerosis
And according to Dr. Grant, about 30 percent of cancer deaths -- which amounts to 2 million worldwide and 200,000 in the United States -- could be prevented each year with higher levels of vitamin D.
However, most people only get 250-300 IU a day from their diet, so another source -- ideally the sun -- is essential.
Where You Live Impacts Your Cancer Risk
The evidence is very clear that the farther away from the equator you live, the higher your risk of dying from cancer becomes. In other words, those who live in higher latitudes have higher cancer rates than those living in lower latitudes.
The difference is actually quite significant.
According to Dr. Grant, people living in Iceland have cancer rates of 90 per 100,000 population per year. Those in the tropics, meanwhile, have rates of 25 per 100,000!
And, he says, the majority of cancer deaths in the United States are from vitamin-D-sensitive cancers. So making sure your levels are optimized should be a no-brainer, but don’t rely on your physician to check for it. Most don’t do it automatically.
How to Have Your Vitamin D Levels Tested
I believe that with all that is known about vitamin D, it is medically negligent not to perform a vitamin D test on someone who has a dangerous cancer.
A simple blood test can tell you your levels, but please bear in mind when you go for the test that there are TWO vitamin D tests: 1,25(OH)D and 25(OH)D.
25(OH)D is the better marker of overall D status. It is this marker that is most strongly associated with overall health.
The correct test your doctor needs to order is 25(OH)D, also called 25-hydroxyvitamin D.
When you receive your results, please note the difference between normal and optimal. You don't want to be average here; you want to be optimally healthy. There is a high likelihood that the reference ranges of your lab will not be correct.
So please be sure and use the values listed in this report to guide your treatment. Normal 25-hydroxyvitamin D lab values are 20-56 ng/ml (50-140 nmol/l). However, this range is far too broad to be ideal.
In fact, your vitamin D level should never be below 32 ng/ml, and any levels below 20 ng/ml are considered serious deficiency states. Remember, the late winter average of 25-hydroxyvitamin D in the United States, is only about 15-18 ng/ml!
The OPTIMAL value that you’re looking for is 50-55 ng/ml (115-128 nmol/l).
Keeping your level in this range, and even erring toward the higher numbers in this range, is going to give you the most protective benefit.
How Long Should You Spend in the Sun?
A common myth is that occasional exposure of your face and hands to sunlight is "sufficient" for vitamin D nutrition. For most of us, this is an absolutely inadequate exposure to move vitamin levels to the healthy range.
You need to expose large portions of your skin to the sun, and you need to do it for more than a few minutes.
In Caucasian skin, an equilibrium occurs within 20 minutes of ultraviolet exposure. It can take three to six times longer for darkly pigmented skin to reach the equilibrium concentration of skin vitamin D. So, bearing in mind that you need to gradually increase your time, starting in the spring, you should be aiming toward exposing large areas of your skin to the sun, anywhere from 20 minutes at a time to two hours at a time, depending on your skin type and environmental factors.
Longer exposures will be needed if sunbathing occurs at off-peak times for ultraviolet light (before 12 p.m. or after 3 p.m.) or at the beginning or end of the summer (April or September).
What About During the Winter?
In the winter months if you’ve had your vitamin D levels tested and found them to be low, a vitamin D3 supplement (cholecalciferol), which is the type of vitamin D found naturally in foods like eggs, organ meats, animal fat, cod liver oil, and fish, can be used. Continue to have your vitamin D levels monitored during this time, though, so you don’t overdose.
To learn more about how to use sunlight for your health -- and the dangers of not getting enough -- keep an eye out for my new book, Dark Deception, which is coming out shortly.