Asthma

Updated 26 July 2016

Vitamin D supplements may improve asthma symptoms

Vitamin D supplements, in addition to regular inhalers, may help asthma sufferers breathe a little easier.

0

Asthma sufferers who received vitamin D supplements for six months, in addition to their regular inhalers, could breathe a little easier than those who relied only on the inhalers, according to a recent study in Iran.

The researchers say the results – if confirmed by larger studies – might help the many people who sometimes have troublesome asthma symptoms even though they use medication.

"It does build some on the growing amount of data that shows vitamin D might help those affected by asthma," Dr. Mario Castro, who was not involved in the study, told Reuters Health.

But Castro, a professor of Pulmonary and Critical Care Medicine at Washington University School of Medicine in St. Louis, Missouri, pointed out that the researchers only measured patients' lung function, and not whether or not their symptoms improved.

"Given that vitamin D is a relatively benign supplement," the small improvement in lung function "would be worthwhile if it was confirmed with other improvements in asthma control," he said, such as fewer symptoms or a reduced need for medication.

Asthma rates increasing 

About one in 12 individuals, or 25 million people, have asthma in the U.S. alone. In the last decade, the number of people with asthma has grown by about 15 percent.

Higher rates of asthma in northern climates have led some researchers to suspect that less sunlight – and therefore less vitamin D – could be playing a role. Several studies have shown a link between low vitamin D levels and asthma.

Read: 
Sun protects against childhood asthma

The new study, by Dr. Saba Arshi at the Medical University of Tehran and colleagues, involved 130 children and adults with mild-to-moderate asthma.

Everyone received asthma medication in a dry powder inhaler (budesonide, sold in the U.S. as Pulmicort, or budesonide plus formoterol, sold in the U.S. as Symbicort).

In addition, half the group was randomly chosen to receive high doses of vitamin D for six months. The first dose, 100,000 units, was given by injection; then patients were instructed to take 50,000 units orally once a week.

After eight weeks, when the researchers measured the amount of air patients could exhale in one second, both groups had improved to roughly the same extent. But after 28 weeks, that amount had improved by about 20 percent in the patients who received vitamin D supplements, versus about 7 percent among those who only used the inhaler.

The authors did not respond to questions about the study, which was published in Annals of Allergy, Asthma and Immunology.

Not recommended for everyone

Castro thinks the patients in the study weren't particularly deficient in vitamin D.

"This is another weakness as they enrolled patients with normal vitamin D levels, so (they're) unlikely to see a treatment effect," Castro said.

He would not recommend that patients with asthma take vitamin D supplements based on this study and one of his own studies, though his research found some people with deficient levels improved after supplementation.

Dr. Doug Brugge, a professor of public health and community medicine at Tufts School of Medicine in Boston, said he thought the study added to the field of asthma and vitamin D research.

"I think it adds some evidence that vitamin D may be beneficial in terms of treating asthma, which in turn contributes some evidence that vitamin D is a factor in asthma," Brugge, who wasn't involved in the study, told Reuters Health.

He noted that most asthma research has focused on children, but this one included adults. "There really is a need for more research on asthma in adults," he said.

Study not convincing enough

But Brugge, who has studied the possible environmental causes of childhood asthma, said the study would have been more convincing if researchers had checked whether patients took their medication as prescribed (other than asking by phone) and included any exposure to environmental triggers of asthma.

"It leaves a little doubt in my mind . . . what if the intervention group was adhering to the medication more than the control group? I think it's unlikely but it would have been nice to see that a little more clearly addressed," said Brugge.

"Adherence is a big problem," said Brugge, referring to medication use in general. "Non-adherence is more common than adherence."

Read: Your 10 point action plan to manage your asthma

Brugge too thinks more studies are needed before anyone can assume that vitamin D would help people with asthma.

"I think it's a reasonable hypothesis and their study and some other studies provide evidence it might be true. But I don't think it's proven yet," said Brugge.

Read more:

Why you shouldn’t take calcium without Vitamin D
Vitamin D deficiency a risk factor for dementia
The wow about vitamin D

Image: Vitamin D capsules from Shutterstock

See breaking news and the hottest health tips before anybody else by joining South Africa’s biggest and best health community, like health24 on Facebook now!

 

Read Health24’s Comments Policy

Comment on this story
0 comments
Comments have been closed for this article.

Ask the Expert

Asthma Expert

Professor Keertan Dheda has received of several prestigious awards including the 2014 Oppenheimer Award, and has published over 160 peer-reviewed papers and holds 3 patents related to new TB diagnostic or infection control technologies. He serves on the editorial board of the journals PLoS One, the International Journal of Tuberculosis and Lung Disease, American Journal of Respiratory and Critical Medicine, Lancet Respiratory Diseases and Nature Scientific Reports, amongst others.Read his full biography at the University of Cape Town Lung Institute

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules