But vitamin D doesn’t seem to reduce the number of these exacerbations. That said, vitamin D did benefit a small group of 30 people in the study who had severely low vitamin D levels when the study began.

New research, however, may dash some of this enthusiasm for people with COPD , an umbrella name for chronic lung diseases , including chronic bronchitis and emphysema . People with COPD often experience a worsening of their breathlessness and other symptoms (exacerbations) throughout the course of their disease.

Low Vitamin D Levels and COPD

Vitamin D is often referred to as the sunshine vitamin because our 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.

The new study included 182 people with COPD. Participants orally received 100,000 IU of vitamin D or an inactive placebo monthly for a year. There were 468 exacerbations during the study period, and there was no difference in the numbers between the different groups. There were also no differences in time to the first exacerbation between those who received vitamin D and those who did not.

People who took vitamin D did not report greater improvements in their quality of life or the number of times they were hospitalized for COPD, the study shows. Vitamin D also had no bearing on their lung function and risk of death.

However, in looking at a small subset of people with severely low vitamin D, the rate of exacerbations decreased among people who received vitamin D, the study showed. But the researchers note that the number of people in their study with severely low vitamin D was very small, so future studies to look at a possible benefit from vitamin D in people with severely low vitamin D levels need to be done to support the findings.