Quality evidence shows that supplementing with vitamin D can reduce the risk of severe asthma attacks. [Photo: Bigstock]

Vitamin D can reduce asthma attacks

12 September, 2016

Natural Health News —  Taking an oral vitamin D supplement, in addition to standard asthma medication, is likely to reduce the occurence of severe asthma attacks.

That is the conclusion of a major new review paper published by the prestigious Cochrane Review in the Cochrane Library.

Asthma is a common chronic disease affecting about 300 million people worldwide. Sufferers can experiecne a range of distressing symptoms such as wheezing, coughing, chest tightness and shortness of breath.

We have previously reported on evidence that vitamin D deficiency can raise the risk of a severe asthma attack.

What you need to know

» Previous studies have shown that vitamin D may help lower the risk of asthma attacks, for instance by helping to reduce the risk of upper respiratory infections.

» A major UK review has looked at evidence form the best quality trials on vitamin D and asthma and found that supplementing, alongside conventional medication, can help cut the risk of severe attacks by half.

» The data looked mainly at those with mild to moderate asthma. More study is needed, say the reviewers, to say conclusively whether supplements could help those suffering from severe asthma.

Because of this and other studies showing that it might help to reduce upper respiratory infections, (such as the common cold), which can lead to exacerbations of asthma symptoms, there has been a growing interest in the potential role of vitamin D in asthma management.

Several clinical trials have tested whether taking vitamin D as a supplement has an effect on asthma attacks, symptoms and lung function in children and adults with asthma.

High quality evidence

The team of Cochrane researchers identified seven high quality randomised trials involving 435 children and two studies, involving 658 adults. On average the studies lasted for between six and 12 months.

The study participants were ethnically diverse, reflecting the broad range of global geographic settings, including Canada, India, Japan, Poland, the UK, and the US. The majority of people studied had mild to moderate asthma, and a minority had severe asthma. Most people continued to take their usual asthma medication while participating in the studies.

What they found

Key findings from the review were:

  • Oral vitamin D supplement reduced the risk of severe asthma attacks requiring hospital admission or emergency department attendance by half – from 6% to around 3%.
  • Vitamin D supplementation reduced the rate of asthma attacks needing treatment with steroid tablets. These results are based largely on trials in adults.

Vitamin D did not improve lung function or day-to-day asthma symptoms, nor did it increase the risk of side effects at the doses that were tested.

Lead author, Professor Adrian Martineau from the Asthma UK Centre for Applied Research, Queen Mary University of London, noted: “We found that taking a vitamin D supplement in addition to standard asthma treatment significantly reduced the risk of severe asthma attached, without causing side effects.”

He added, however, that because the majority of those studied had mild to moderate asthma, it was difficult to extrapolate the findings to those with severe asthma. More research was needed, Martineau said, to discern, for instance, if vitamin D was useful to all sufferers or just those with low vitamin D levels.

Nevertheless, the findings are very good news for those suffering from asthma who are looking for more natural ways to support better respiratory health or who wish to reduce the risk of taking potentialy harmful medications such as steriods.