Vitamin D provides no relief from chronic obstructive pulmonary disease

By Dr. Ananya Mandal, MDJan 17 2012

A latest study shows that people with moderate or severe lung disease, taking large amounts of vitamin D was not linked to any symptom relief.

Earlier studies have suggested that up to three quarters of people with severe chronic obstructive pulmonary disease, or COPD, are deficient in the vitamin. So it was thought that giving them extra vitamin D might help prevent exacerbations in symptoms or trips to the hospital because of shortness of breath or mucus in the airways. Belgian researchers have refuted this claim.

“Supplementation with vitamin D is not going to cure their disease,” said Dr. Wim Janssens, one of the study's authors from University Hospitals Leuven. “It is again clear for COPD patients that these exacerbations are really hard to treat,” and prevent, Janssens told Reuters Health. “There are a lot of relapses. We're basically failing in treating these.”

For the study Janssens and his colleagues randomly assigned 182 people at their hospital with moderate to severe forms of the disease to take 100,000 IU of vitamin D, or a vitamin-free placebo pill, every four weeks for a year. One hundred and fifty of them finished the study.

Over that year, patients on vitamin D reported a total of 229 exacerbations in symptoms, for an average of 2.8 exacerbations in each patient. That was not statistically different from the 239 exacerbations, or 2.9 per patient, among those taking the placebo. Symptoms were severe enough to send patients taking vitamin D to the hospital 79 times during the study, and people in the placebo group 73 times.

There was also no difference between the two groups in the amount of time until patients had their first exacerbation, or in measures of lung functioning, fatigue or the risk of death. The researchers did find that among 30 people who had a very severe vitamin D deficiency at the start of the study, those taking the supplements had fewer problems with symptoms.

“That would indicate that if there's any effect, there might be something in patients with really low levels. That's not the majority of patients with COPD,” said Dr. Ken Kunisaki, from the Minneapolis VA Healthcare System. More research would be needed to confirm if the vitamin is of any benefit even in those very deficient patients, added Kunisaki, who has also studied vitamin D in COPD but wasn't involved in the new research. He said the current findings are in line with other research suggesting that although vitamin D deficiency might be more common in people with COPD, higher levels don't necessarily seem to equate with fewer symptoms. “Unfortunately the results have been somewhat disappointing,” Kunisaki said. “Right now there's no evidence that patients with COPD are going to benefit from additional vitamin D.”

Though vitamin D is most often associated with bone health and osteoporosis, Janssens said the theory has been that the vitamin may help reduce inflammation, including inflammation in the airways that worsens COPD symptoms, such as coughing and trouble breathing. COPD is irreversible impairment of lung function, including emphysema and chronic bronchitis, often caused by smoking. One large national health survey suggests some 24 million Americans have the condition, according to the Centers for Disease Control and Prevention.

Researchers have also proposed that vitamin D may be helpful in patients with multiple sclerosis or tuberculosis, among other diseases, but studies generally haven't panned out, Janssens and his colleagues wrote in their report, published Monday in the Annals of Internal Medicine. He said that in spite of his team's lack of positive findings, people with or without COPD shouldn't ignore very low vitamin D levels. “If you're deficient, you need supplementation to normal levels just to treat your bone, to protect from osteoporosis and fractures,” he said. “If you (have) severe deficiency, supplementation might also be effective for inflammation” associated with COPD.

Barry Make, agrees. He is a pulmonologist at National Jewish Health in Denver. “The study suggests that going forward maybe we should study preventing exacerbations in people that have low vitamin D levels,” he says. “Vitamin D is important to measure and if it is low, it makes sense to supplement,” he says.

Adam Wanner, a pulmonologist at the University of Miami Miller School of Medicine, says the jury is still out on what role vitamin D supplements have, and in which COPD patients. “There were no benefits in terms of exacerbations in the study, but when they looked at the subset of those who had severe vitamin D deficiency, there was a benefit,” he says. “This is an important study in the sense that it helps us design future studies.”

The results of the study are in the eye of the beholder, says Michael Holick. He is the director of the Vitamin D, Skin, and Bone Research Lab at Boston University. Holick has been championing vitamin D for years. “Vitamin D has benefit above and beyond bone health,” he says. “There was a significant benefit for those people in the study who were most deficient.”

Kunisaki however cautioned that researchers still don't know whether there are long-term risks associated with taking high doses of vitamin D or other vitamins.

Vitamin D is often referred to as the sunshine vitamin because human bodies produce it when exposed to sunlight. The Institute of Medicine recommends that people aged 1 to 70 take in 600 international units (IUs) of vitamin D per day, and people older than 70 should aim for 800 IUs. Some foods like fish and fortified dairy and juice products are rich in vitamin D, but supplements are also used to raise blood levels.