Researchers from Queen Mary University of London conducted a randomised trial on 240 patients with COPD in and around London.
Half of the patients (122) received vitamin D supplements and the other half (118) received an equivalent placebo.
The risk, severity and duration of flare-ups was then compared between the two groups.
Flare-ups (also referred to as 'exacerbations') are when a COPD patient's usual symptoms (coughing, excess mucus, shortness of breath, tightness in chest) get worse and stay worse, sometimes resulting in hospitalisation.
However, researchers did find vitamin D supplementation modestly reduced the severity and duration of flare-up symptoms in all patients in the vitamin D group, regardless of their baseline vitamin D levels, compared to the placebo group.
This is the first clinical trial to investigate the impact of vitamin D supplementation on severity and duration of COPD symptoms, researchers said.
One previous trial has linked vitamin D to a reduction in COPD disease flare ups but this was limited to patients with very severe conditions. This trial is larger and studied patients with a much broader spectrum of diseases, ranging from mild to severe, researchers said.
"Our findings suggest that patients with COPD should have their vitamin D status tested and should begin taking supplements if their levels are found to be low," said Martineau.
The research was published in the journal Lancet Respiratory Medicine.
