Oral vitamin D supplementation “safely and substantially” lowered the moderate/severe COPD exacerbation rates in patients with baseline 25-hydroxyvitamin D levels of less than 25 nmol/L, according to a systematic review and meta-analysis recently published in Thorax.

“Consistent associations between circulating concentrations of 25-hydroxyvitamin D and risk of COPD exacerbation have not been demonstrated,” David A. Jolliffe, PhD, of The London School of Medicine and Dentistry at Queen Mary University of London and colleagues wrote.