PITTSBURGH (KDKA) – Are vitamins and asthma related?

Previous studies show that lung function is worse in asthmatic children with a vitamin D deficiency, even when treated with inhaled steroids.

But the way these studies have been designed, only a link can be established — not cause and effect.

That’s why doctors at Allegheny General Hospital are taking part in a multi-center, randomized, placebo-controlled clinical trial in adults.

“This is actually your true best test to find a cause and effect relationship,” Dr, Deborah Gentile, an allergist at AGH, said.

Obesity, living in the city, and being African-American are common risk factors for both vitamin D deficiency and asthma.

So is it the vitamin D or some other factor that makes asthma harder to control? That’s what this clinical trial is designed to figure out.

Right now, they’re still screening for 12 participants to be randomly assigned to take 5,000 units of vitamin D daily or placebo.

To participate you must be 18 or older and have asthma and take controller medications, such as an inhaled steroid and still have symptoms several times a week.

You will not be eligible if you’ve smoked within the last year or if you already take high-dose vitamin D.

Aimee Fogarty is being screened today.

“My main things in the fall are ragweed, and dust mites are a killer for me. In the spring, it’s more grass,” she said.

Her inhaled steroids aren’t cutting it.

“They normally do, but right now, I’m having a little bit of a difficult time, and had to double the dose,” Fogarty said. “The taking of the steroids, I just don’t like it. It’s bothering me that I have to take a steroid to breathe better.”

People eligible for the study get a blood test for a vitamin D level, and breathing tests. Then, they are randomly assigned to a treatment group.

“Some will get placebo. Some will get vitamin D,” Dr. Gentile said.

For six months, lung function and symptoms will be closely watched.

“On the one hand, we may find it works, and it very inexpensively improves the outcomes in our patients. On the other hand, if it’s negative and we find out it doesn’t help, we know that it doesn’t help,” Dr. Gentile said.

“My whole family has it,” Fogarty said. “And if this can help people in any way, I’d like to be a part of it.”