By Robert Bazell

Chief science and health correspondent

NBC News

updated 5:54 p.m. MT, Mon., Jan. 19, 2004

Tamara Smith visits a tanning parlor when she can’t be outside in the sun. “I’m always indoors. I don’t go outside,” says Smith.

Many doctors say ultraviolet light from the sun or a tanning machine is dangerous because of the risks associated with skin cancer. But some health experts, such as Dr. Michael Holick of Boston University, disagree.

“I believe that Americans have gone overboard with their fear of the sun. I think that sensible exposure to sunlight is really important for your overall health and well-being,” says Holick.

The reason for the concern is vitamin D, essential for bone strength and other health needs, which our skin makes through exposure to the sun’s ultraviolet rays.

We need 1,000 units of vitamin D a day, but a glass of milk supplies only 100 units and a multivitamin only 400. So most people need the sun in order to avoid deficiency.

Sunscreens can reduce vitamin D production
Now, new research has found that wearing sunscreen continuously can reduce the amount of vitamin D a person is able to make.

“We looked at individuals that always wore a sunscreen before they went outside. … And we found that, indeed at the end of the summer, they were deficient in vitamin D,” says Holick. “And so we have shown over and over again that adults, even if they’re on a multivitamin, and drinking milk, if they always wear sun protection, or avoid any direct sun exposure, they’re at high risk of developing vitamin D deficiency.”

Rooftop measurements of sunlight show that, for most people, getting enough sunlight exposure at this time of year is not easy, even for people who don’t regularly wear sunscreen. In the middle of the winter on a very sunny day in a city as far north as Boston, there’s not enough sunlight for people to get sufficient quantities of vitamin D.

The good news is that if you get enough sun during the rest of the year, it carries you through the winter, says Holick.

Or there are machines. In Holick’s lab he put young people in tanning machines and measured their bone density.

“Tanners had higher bone density on average than non-tanners,” says Holick.

Still, he cautions against the dangers of skin cancer and warns people not to go overboard. However, it is critical, he says, to realize the sun’s rays are not always our enemy.

© 2007 MSNBC Interactive

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Twenty minutes’ lying in the sun could provide your best chance of avoiding colds and flu, according to new research which demonstrates that vitamin D, not vitamin C, provides the most efficient protection against cold viruses.

Read the rest of this article: The New Zealand Herald

Canadian Cancer Society announces national program to prevent cancer using vitamin D

Canada has done what the U.S. refuses to do: Protect the health of its people through a national program of encouraging vitamin D supplementation. While U.S. cancer groups like the American Cancer Society stubbornly refuse to acknowledge the benefits of vitamin D supplements in cancer prevention, the Canadian Cancer Society is launching a program to make sure every Canadian citizen receives a level of vitamin D sufficient to prevent most cancers, including breast cancer.

Read the rest of this article: Natural News

Exciting new research conducted at the Creighton University School of Medicine in Nebraska has revealed that supplementing with vitamin D and calcium can reduce your risk of cancer by an astonishing 77 percent. This includes breast cancer, colon cancer, skin cancer and other forms of cancer. This research provides strong new evidence that vitamin D is the single most effective medicine against cancer, far outpacing the benefits of any cancer drug known to modern science.

Read the rest of this article: Natural News

Despite efforts to increase knowledge and emphasis on osteoporosis prevention and treatment, research indicates that many women treated for osteoporosis have low levels of vitamin D, a nutrient necessary for adequate bone mineralization.

A recent study involved 1,536 postmenopausal women from 61 study sites who had been taking medications for the treatment of osteoporosis for a minimum of three months. Participants were allowed to have used vitamin D supplements as long as the dosage had remained consistent.

Overall, 52 percent of the women had vitamin D levels considered inadequate. Sixty-three percent of women who reported a supplemental intake of 400 IU’s or less had inadequate vitamin D levels compared to 45 percent of those whose intake was 400 IU’s or greater. Lower levels were also associated with the lack of physician counseling regarding the importance of vitamin D in bone health.

The results of this study emphasize the need for greater education of the public and physicians regarding the significance of vitamin D status in the care of postmenopausal women with osteoporosis.

J Clin Endocrinol Metab 2005 Jun;90(6):3215-24