How sun-savvy are you? And does it really make any difference? The truth is, that big round mass of hot gases in the sky has much more to do with your health than you probably ever imagined. The sun is a star that supplies the heat that sustains life on earth and controls our weather and climate. We know that from our schooldays. But what no one drove home until recently was the critical role that the sun plays in helping your body convert vitamin D, making it usable for your body’s overall health.
Recent research shows that most Americans need to increase their intake of D in order to ward off disease, decrease pain and reap major health benefits. Our book, The Vitamin D Cure (Wiley, January 2008), delivers the exciting lowdown on the Sunshine Vitamin D.
These revelations are important and unprecedented because only in recent years have researchers and some physicians become fully aware of the huge difference vitamin D can make in people’s health. Supplementing your D level can actually prevent cancer, diabetes, arthritis and heart disease.
Why D Matters
Doctors often find low D levels in people with fatigue and back pain as well as those who suffer from seasonal affective disorder (SAD), autoimmune diseases, obesity, heart disease and cancer.
Human beings absolutely need sunlight to make vitamin D, but the UVB rays that people require are the same rays that are blocked by sunscreen—and you can only get these rays in the middle of the day, spring to fall. So, you have to spend time outside, sunscreen-free, to get enough vitamin D. That means if you have an inside job, you also need to take a supplement.
A good starting dose for most adults is 2000/day. The amount depends on weight and other risk factors. You can take the book’s quiz to determine your risk for low D levels and exactly how much D you should be taking.
Sorting UV Light
Ultraviolet light comes in A, B and C spectrums. All UVC is absorbed in the ozone so you don’t get UVC when you’re outside. Small amounts of UVB penetrate the ozone, depending on its thickness, angle of the sun, cloud cover, upper atmospheric changes and solar activity. The variable that dominates UVB changes that pass through the ozone is the angle of the sun where you live. And, UVA penetrates the ozone year-round.
Here’s how it breaks down:
Indoor Tanning Beds
Indoor tanning bulbs vary in intensity and type from one salon to another and from bed to bed, which makes this kind of tanning unpredictable. Some beds have a mixture of UVA, UVB and no UVC, but most tanning beds produce all three—or just lots of UVA because it tans faster. Overexposure to any of these wavelengths isn’t healthy.
The Upshot
About 60% of Americans are vitamin D deficient, so it makes no sense to tell everyone to cover up. You don’t want to burn, of course, but you do want to produce vitamin D.
Remember that SPF 8 (applied correctly) blocks more than 95% of UVB rays; SPF 15, about 100%. So, it’s best to apply sunscreen only after you’ve been outside long enough for your body to make adequate vitamin D.
For safe D supplementation, follow the guidelines in The Vitamin D Cure. You can also refer to www.thevitamindcure.com for helpful tools, including a D-deficiency risk calculator, a sun exposure calculator, newsletter and links to vitamin D science.
Just Three Things
A tiny vitamin supplement, a little sun and some dietary fixes can alter your health dramatically.
Diane Stafford is a former editor-in-chief of five magazines and the author of twelve books. James E. Dowd, M.D., F.A.C.R., is the founder of the Arthritis Institute of Michigan and the Michigan Arthritis Research Center. He is a rheumatologist in private practice in Brighton, MI.
