With news this week that everybody living in London is at risk from toxic air particles   that can trigger health problems like asthma, it may be some comfort to learn that a new study has found that asthmatics could actually halve their risk of having a severe attack by merely taking a Vitamin D supplement. Published in The Lancet Respiratory Medicine, the new study into A&E asthma admissions was carried out by researchers based at Queen Mary University of London, who found that there was a 3% drop in people requiring hospital treatment. Moreover, with taking the 2p-a-tablet supplements – widely available in supermarkets and pharmacies - there was found to be an incredible 30% decrease in asthma sufferers that needed treatment or steroids for attacks. Researchers analysed 955 participants for a year, with focus being placed on their Vitamin D intake contrasted to the asthma attacks they had. No participant had any adverse side effects. The authors of the study say that Vitamin D supplements are both an inexpensive and effective method of reducing the frequency of potentially deadly asthma attacks. “These results add to the ever growing body of evidence that vitamin D can support immune function as well as bone health,” commented the study lead researcher Professor Adrian Martineau. “Vitamin D is safe to take and relatively inexpensive so supplementation represents a potentially cost-effective strategy to reduce this problem.” In the UK alone, an estimated 5.4 million people require treatment for asthma; 1.1 million children (1 in 11) and 4.3 million adults (1 in 12). Unfortunately, the UK has one of the highest asthma rates across Europe and 3 people each day will lose their life to the condition. In 2015 (the most recent data available) 1,468 people were found to have died because of asthma, and the condition costs the NHS an estimated £1b per year for the treatment and care of those with asthma. Death generally occurs with asthma as symptoms worsen, especially during viral upper respiratory infections. Vitamin D is said to improve immune responses to respiratory viruses and dampening down harmful airway inflammation, therefore managing to prevent asthma attacks. It is widely known that being in the sunlight can encourage the body to produce Vitamin D, but the UK isn’t often experiencing good enough weather to want to venture outdoors. This leaves supplements and getting the vitamin in diet. “In the UK, sunlight only contains enough UVB to stimulate production of vitamin D in the skin between April and October – in Winter and early Spring, it won’t provide any Vitamin D,” added Prof Martineau. “UVB is also a risk factor for skin cancer of course – so from a safety perspective it makes sense to be careful with exposure to sunlight, and keep Vitamin D levels up during winter and early spring by taking a regular supplement.” Professor Hywel Williams, Director of the National Institute for Health Research Health Technology Assessment Programme, said: “The results of this NIHR-funded study brings together evidence from several other studies from over the world and is an important contribution to reducing uncertainties on whether Vitamin D is helpful for asthma – a common condition that impacts on many thousands of people worldwide.” Dr David Jolliffe from QMUL, first author on the paper, added: “Our results are largely based on data from adults with mild to moderate asthma: children and adults with severe asthma were relatively under-represented in the dataset, so our findings cannot necessarily be generalised to these patient groups at this stage. “Further clinical trials are on-going internationally, and we hope to include data from them in a future analysis to determine whether the promise of today’s results is confirmed in an even larger and more diverse group of patients.” Dr Pooja Takhar, of Asthma UK, said: “This is a promising area of research. But it is only one piece of a very large jigsaw and more evidence is needed.”