Mother and daughterFor years, experts and people with psoriasis scratched their heads in despair over medical science’s inability to fight this troubling skin disease. Then groundbreaking research by Michael F. Holick, M.D., Ph.D., director of the General Clinical Research Center and chief of the Section of Endocrinology, Diabetes and Metabolism at Boston University Medical Center, unleashed the dramatic healing power of vitamin D and revealed just how to make it work against psoriasis.
Vibrant, healthy skin seems to just happen for some people. Like clockwork, they shed skin cells in the form of minute, invisible flakes while new cells push to the surface in a 15-stage cycle that is as natural as it is uneventful. And every 28 to 30 days, they’re clad in a completely new suit of skin. Not so for people with psoriasis. It’s as if parts of the skin-renewing cycle were put on fast-forward–really fast-forward. Within four to five days, the affected patches of skin, called plaques, undergo just five changes before they pile up like the Sunday paper. The result: red, itchy, scaly plaques that often cover the knees, elbows and scalp.
Nor does psoriasis stop at the surface. “It ranges from localized mild patches on the skin to a totally disabling total body disease,” says Nicholas Lowe, M.D., clinical professor of dermatology at the University of California, Los Angeles, UCLA School of Medicine. About 25 percent of the four to five million psoriasis cases in the United States are so bad that people are completely disabled, often with a crippling form of arthritis.
Special receptors in your skin also make use of sunlight-produced vitamin D, a fact that has led some to try tanning in an attempt to end their psoriasis. In fact, nude sunbathing at the Dead Sea in Israel has become such a popular treatment for psoriasis that the Wall Street Journal suggested the influx (about 10,000 visitors a year and growing!) is creating a modern Mecca for psoriasis treatment.
Researchers exploring the role of vitamin D receptors in the skin have found a way to help people with psoriasis. Dr. Holick discovered that skin cells have receptors for what is called activated vitamin D, essentially the hormone that prevents skin cells from growing and shedding too rapidly.
The next step was to develop a super potent yet nontoxic form of activated vitamin D, strong enough to slow the growth of psoriatic skin cells. “We wanted to take advantage of the observation that we had made, using a high enough concentration to alter the growth of the skin cells without harm,” Dr. Holick explains.
Applied to the skin as an ointment (Dovonex), activated vitamin D, available only by prescription, not only slows skin cell growth to levels much closer to normal but also reduces itching and inflammation, says Dr. Holick. “Among those who use Dovonex topically, upward of 50 to 60 percent have seen significant improvement,” he says. Such improvement usually begins to appear in two to three weeks.
Wouldn’t mega-doses of over-the-counter vitamin D have the same positive effect on psoriasis? Not at all, says Dr. Holick. “The reason is that the body is very particular about the amount of vitamin D that it takes in. It will not make any more activated vitamin D, regardless of how much of the vitamin you take. You can become vitamin D-intoxicated, but you won’t be able to treat your psoriasis,” says Dr. Holick.

SOURCES: From the Rodale book, Prevention’s Healing with Vitamins
Courtesy of The Vitamin D Council