In power of vitamin D, hope for a new disease fighter

In a Newark laboratory, researchers watch as mice stricken with multiple sclerosis suddenly walk. They peer into microscopes and see the growth of breast cancer cells dramatically slowed.


They are examining, up close, the power of vitamin D.

"We're believers," said Sylvia Christakos, a longtime vitamin researcher at UMDNJ-New Jersey Medical School.

Many others are following. A spate of provocative studies shows the potential health benefits of vitamin D on everything from breast, prostate and colon cancer to auto- immune disorders such as Type I diabetes, rheumatoid arthritis, lupus and multiple sclerosis.

The so-called "sunshine vitamin" may even protect the heart.

Some researchers, citing widespread vitamin D deficiencies among Americans, call current federal guidelines outdated and argue most people need far more of the nutrient than they get from food, multi-vitamins and the sun.

Others say more research is needed before Americans start downing supplements or exposing unprotected skin to height-of-the- day sun, whose ultraviolet rays help create the vitamin.

Few researchers, however, have studied the nutrient more closely than Christakos.

"There is finally more of a recognition of the value of vitamin D to prevent various diseases," she said. "But it's cheap and over-the-counter so you won't turn on the television and see commercials pushing vitamin D."

In a review scheduled for publi cation this week in the online Journal of Cellular Biochemistry, Christakos and her team conclude proper blood levels of vitamin D can protect people from multiple sclerosis. The review said the nutrient may help maintain balance in the immune system.

The team looked at MS in mice, and found those treated early with an active form of vitamin D improved dramatically. The stricken mice, once paralyzed, were able to walk, though Christakos said that does not mean the same will happen for people with MS.

The lab has gone a step further to show how vitamin D may work on a genetic level. Working with researchers from Stanford University, they showed how vitamin D likely inhibits a key inflammatory response involved in MS.

The data on vitamin D is accumulating. For example:

A Canadian study found women with breast cancer were nearly twice as likely to see their cancer spread, and far more likely to die, if deficient in the vitamin.

A 2007 study in the American Journal of Clinical Nutrition concluded improving calcium and vitamin D levels substantially reduces all cancer risk in post-menopausal women.

In last year's New England Journal of Medicine, researcher Michael F. Holick of Boston University School of Medicine cited a study that found elderly French women given 1,200 mg of calcium and 800 international units (IU) of vitamin D daily for three years reduced their risk of hip fracture by 43 percent.

Holick cited another study that found women who took more than 400 IU of vitamin D had a 42 percent reduced risk of developing multiple sclerosis. Another study found that 10,366 Finnish children who were given 2,000 IU of vitamin D per day during their first year of life and were followed for 31 years had their risk of developing Type I diabetes reduced by 80 percent.

Holick said Americans should take at least 1,000 IU of vitamin D daily as well as a multivitamin with another 400 IU. Christakos said vitamin D supplements are especially important for those at risk of immune disorders, such as siblings of people with Type I diabetes or MS.

Government guidelines, however, recommend just 200 IU for those under 50; 400 for those 51-70; and 600 for those over 70.

Jennifer Koentop, a spokeswoman for the U.S. Department of Health and Human Services, said the government is negotiating with the Institute of Medicine, a national advisory organization, to review the vitamin D guidelines.

Humans once routinely absorbed vitamin D from the sun, but when jobs and society moved in doors exposure to sunlight dropped. Holick estimates half of all Americans are vitamin D defi cient. Deficiency rates among African-Americans may be higher.

Reinhold Veith, a researcher at the University of Toronto, said people can safely put on a bathing suit and expose much of their skin, without sunscreen, for as little as five minutes several times a week to obtain vitamin D.

Most dermatologists disagree, however. The American Academy of Dermatology, on its website, said people who want additional vitamin D should use supplements to prevent skin cancer and damage.

Debate continues over supplements, too. Laura Byham-Gray, associate professor of nutritional sciences at the UMDNJ-School of Health Related Professions, does not recommend higher doses.

"What we consider a vitamin D deficiency is still under debate," she said. She cites the hype that once surrounded vitamin E, which researchers later learned actually increased mortality.

Vitamin D proponents said as much as 10,000 IU daily will not cause toxicity.

"Policy makers want a high level of evidence before committing themselves," Veith said. "But all the accumulating evidence on vita min D has been like a slow rising sun. When do you call it daytime?"