While scientists don't fully understand what triggers MS, some studies have linked low levels of vitamin D with a higher risk of developing the disease. Hayes has been studying this "vitamin D hypothesis" for the past 25 years with the long-term goal of uncovering novel preventive measures and treatments. Over the years, she and her researchers have revealed some of the molecular mechanisms involved in vitamin D's protective actions, and also explained how vitamin D interactions with estrogen may influence MS disease risk and progression in women.
In the current study, which was funded by the National Multiple Sclerosis Society, Hayes' team compared various vitamin D-based treatments to standard MS drugs. In each case, vitamin D-based treatments won out. Mice that received them showed fewer physical symptoms and cellular signs of disease.
First, Hayes' team compared the effectiveness of a single dose of calcitriol to that of a comparable dose of a glucocorticoid, a drug now administered to MS patients who experience a bad neurological episode. Calcitriol came out ahead, inducing a nine-day remission in 92 percent of mice on average, versus a six-day remission in 58 percent for mice that received glucocorticoid.
"So, at least in the animal model, calcitriol is more effective than what's being used in the clinic right now," says Hayes.
Next, Hayes' team tried a weekly dose of calcitriol. They found that a weekly dose reversed the disease and sustained remission indefinitely.
But calcitriol can carry some strong side effects -- it's a "biological sledgehammer" that can raise blood calcium levels in people, Hayes says -- so she tried a third regimen: a single dose of calcitriol, followed by ongoing vitamin D supplements in the diet. This one-two punch "was a runaway success," she says. "One hundred percent
|Contact: Colleen Hayes|
University of Wisconsin-Madison