Meta-analysis of other randomized controlled trials have shown that vitamin D supplementation reduces the risk of acute respiratory infections and exacerbations of asthma.
Adrian Martineau, PhD
Vitamin D has long been proven to benefit bone strength and the prevention osteoporosis. But there is ongoing research to find additional health benefits of this unique nutrient; a recent study suggests supplementation could reduce chronic obstructive pulmonary disease (COPD) exacerbations in patients with a baseline vitamin D level.
Investigators for this study, led by Adrian Martineau, PhD, clinical professor of Respiratory Infection and immunity at Queen Mary University of London, analyzed data from 469 patients from 3 clinical trials across the UK, Belgium, and the Netherlands.
According to the COPD Foundation, about 30 million Americans are affected by COPD. Exacerbations can be triggered by respiratory infections (due to viruses and/or bacteria) or environmental factors, such as air pollution, secondhand smoke or strong scents. Meta-analysis of other randomized controlled trials have shown that vitamin D supplementation reduces the risk of acute respiratory infections and exacerbations of asthma.
There are also a number of trials examining vitamin D supplementation to prevent respiratory infections in children—a population that has increasing rates of asthma.
“Optimal management of COPD is important because this will reduce the rate of exacerbations, which are the major causes of illness, hospitalization, and death in this condition, to a minimum,” Martineau told MD Magazine®.
Results showed that supplementation (ranging from 30 mg per day to 2500 mg per month) did not impact the overall rate of moderate/severe COPD (aIRR 0.94; 95% CI: 0.78 - 1.13). But subjects with a baseline vitamin D level of less than 25 nmol/L showed a reduction in the rate of moderate/severe COPD exacerbations (aIRR 0.55; 95% CI: 0.36 - 0.84). However, those with a baseline level of 25 nmol/L or more did not have reduced exacerbations (aIRR 1.04; 95% CI: 0.85 - 1.27).
“For this subgroup of patients, we’ve found a treatment which is very safe and very inexpensive, which has a big protective effect, conferring a 45% reduction in the rate of moderate/severe attacks of COPD,” Martineau said. “That is a pretty sizable effect, more powerful than a lot of inhaled therapies which can be expensive and which carry significant risk of side effects.”
Investigators theorized that exacerbations in the vitamin D-deficient group could be due to the deficiency, so the supplementation reduces COPD exacerbations. For the group with high vitamin D levels, exacerbations could be due to another source, such as viral susceptibility or an environmental source.
The next step is to do another clinical trial of vitamin D supplementation that is restricted to COPD patients with low vitamin D levels, added Martineau. PRECOVID, an ongoing trial in the Netherlands, is examining the effects of vitamin D supplementation COPD patients with a vitamin D deficiency.
The study, “Vitamin D to prevent exacerbations of COPD: Systematic Review and Meta-analysis of individual participant data from randomized controlled trials”, was published online in the journal Thorax.