Psoriasis
Prescription Vitamin D Delivers Hope
For years, experts and people with psoriasis scratched their heads (not to mention other body parts) 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.
A Plague Called Plaques
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.
While experts say that such prolific skin shedding is caused by some as yet unknown genetic problem, things such as stress, infections, cuts, scrapes, certain medications (quinine, beta-blockers and lithium, among others) and alcohol can also spark flare-ups. "While psoriasis is an inherited disease, a whole series of other events can bring out the disease in a person who is genetically predisposed," says Dr. Lowe.
| Fishing for a Cure Some experts think that there's something fishy about treating psoriasis with fish oil. But at least one study, done several years ago, showed that the fatty acids found in fish may be beneficial after all. In a Finnish study, 80 people with psoriasis took two capsules containing fatty acids from fish three times a day for eight weeks. At the end of the study, 7 people were completely healed, and 13 reported 75 percent healing. Those who showed the best results in the study had the least severe cases, the researchers noted. "It's neither the best treatment for psoriasis nor the only treatment that people should use, but it may be of some benefit," says 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. Thirty-four of the people included in this Finnish study also had psoriatic arthritis, a form of arthritis related to psoriasis. All 34 reported less severe joint pain after taking the capsules. Fatty acids from fish apparently act as an anti-inflammatory, and that action is particularly effective in some cases of psoriatic arthritis that involve considerable inflammation, says Dr. Holick. Atlantic herring and pink salmon are among the fish highest in helpful fatty acids. Unfortunately, you'd have to eat between one and two pounds a day to get close to the dose of fish oil that the volunteers took during the study. So you might want to ask your doctor about taking fish oil capsules to help combat psoriasis. |
| Food Factors These dietary tips may help you keep your psoriasis at bay. Ban the booze. Alcohol and psoriasis apparently go together like martinis and olives. One study of 362 men between ages 19 and 50 found that many drank heavily before they developed psoriasis--twice as much as those who were psoriasis-free. Heavy drinking also increases the risk of infection, which is known to trigger psoriasis, according to the researchers. Give acid the slip. One small study showed a reduction of psoriasis symptoms among people who avoided acidic foods such as coffee, tomatoes, soda and pineapple. If you discover that certain foods cause you problems, listen to your body and avoid them, says 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. Bring on the veggies. Could eating less protein help tame your psoriasis? Some reports have suggested improvement in symptoms when people with psoriasis ate a vegetarian diet low in protein for several weeks. |
Defeating Psoriasis with Vitamin D
Added to milk and other dairy products, vitamin D has long been known as the cure for rickets, a disease that causes bone deformity and stunted growth in children.
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.
Why the Dead Sea? The location's low elevation prevents the sun's harshest rays from reaching sunbathers, allowing them to stay out longer without burning, experts say. The Dead Sea's mineral-rich water, so salty that plants and fish can't survive, is also thought to help psoriasis.
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 superpotent 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.
And all of this is accomplished without the common reaction to megadoses of vitamin D: raised calcium levels, which can cause kidney stones and high blood pressure. "It's purposely formulated as an ointment. That way, it stays in the skin and doesn't usually enter the blood," says Dr. Holick.
Wouldn't megadoses 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 (1,25-dihydroxy vitamin D3), 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.
Virtues of Vitamin A
Although it's reserved for more severe cases, a superpotent form of vitamin A called etretinate (Tegison) is also available for psoriasis, but only by prescription.
Taken orally, activated vitamin A helps skin cells grow to maturity before shedding. Unfortunately, it also has a downside. "When used clinically to have an effect on psoriasis, almost all of the vitamin A derivatives create a series of unwanted side effects," says James G. Kreuger, M.D., Ph.D., assistant professor of medicine at Rockefeller University in New York City, who heads an investigative group in psoriasis research. Side effects include birth defects, dry mouth and hair loss.
In some cases, Dr. Lowe uses both etretinate and six grams of omega fatty acids, which are found in fish oil, to limit any side effects. "We take blood tests when we have people on these drugs, but it's usually okay to combine them," he says.
Unfortunately, taking a regular form of vitamin A won't help psoriasis at all, says Dr. Lowe.
| Prescriptions for Healing Ask your doctor about Dovonex, a prescription topical form of superpotent vitamin D, and etretinate (Tegison), a prescription oral form of superpotent vitamin A. Many doctors also recommend a multivitamin/mineral supplement containing the Daily Values of folic acid and iron. |
The Case for a Multivitamin
Although no one suggests that any vitamin or mineral taken orally can cure psoriasis, there is some evidence that psoriasis itself can cause certain vitamin and mineral deficiencies.
In a study of 50 people hospitalized with psoriasis, researchers found that some were low in protein, iron and folate (the naturally occurring form of folic acid), according to Janet Prystowsky, M.D., Ph.D., assistant professor of dermatology at Columbia Presbyterian Hospital in New York City.
Rapid skin cell growth and shedding deplete stores of protein, iron and folate because psoriatic skin seems to take precedence over other parts of the body, she says. "While nutritional supplementation is not a remedy for psoriasis, it could improve the general health of a person with the disease," according to Dr. Prystowksy.
