Correcting vitamin D deficiency nearly halves the risk of potentially fatal lung attacks in patients with chronic obstructive pulmonary disease (COPD), our latest study has found.
COPD describes several lung conditions, including emphysema and chronic bronchitis, where a person’s airways become inflamed, making it harder to breathe. Almost all COPD deaths are due to lung attacks (termed “exacerbations”) in which symptoms worsen sharply. These are often triggered by viral upper respiratory infections – the type that cause the common cold.
Vitamin D – “the sunshine vitamin” – is best known for its effects on bone, but it also boosts immunity to viral infections. Our previous research at Queen Mary, University of London, has shown that vitamin D supplements protect against asthma attacks and acute respiratory infections, such as colds and flu, in people who have low vitamin D levels to start with.
A number of clinical trials have tested whether vitamin D supplementation might have a role in reducing the risk of COPD attacks, but they have yielded conflicting results. Some show a benefit, others do not.
One way to get a handle on the reason for their different findings is to pool the data from the various studies into a single database and then run analyses to determine whether vitamin D might have stronger protective effects against lung attacks in certain groups of COPD patients compared with others. This approach is known as “individual participant data meta-analysis”.
Our latest study, published in the journal Thorax, reports the findings of such an analysis. We pooled data from 469 patients who took part in one of three clinical trials of vitamin D that were conducted in the UK, Belgium and the Netherlands.