Can Vitamin D Protect Us From Serious Asthma Attacks? – Care2.com
A new review of previous studies shows that taking vitamin D together with conventional asthma treatments appears to reduce the risk of serious asthma attacks, something that for asthma sufferers could be an encouraging finding.
The review, which was carried out by researchers from several institutions working under the banner of the Cochrane Collaboration, involved analyzing nine double-blind, randomized, placebo-controlled trials, which are among the most rigorous trials scientists can conduct. In this analysis the researchers were looking at patients with clinically diagnosed asthma and what effect, if any, taking vitamin D supplements in addition to their asthma medications might have on their likelihood of having serious asthma attacks.
What is vitamin D?
It’s worth just interjecting on what vitamin D actually is.
We produce vitamin D when our skin is exposed to sunlight. Vitamin D deficiency has become a significant health issue, and for our purposes is interesting because people who have severe asthma have shown a tendency to lack vitamin D. It’s not yet clear why that is though.
One theory is that a lack of vitamin D may predispose people to lung infections and compromise healthy immune response. Others suggest that the lack of vitamin D might actually be caused by the asthma itself due to the fact that people can’t go outside and, for example, enjoy exercise for prolonged periods due to their breathing difficulties. Therefore they’re not getting the sunlight they need to produce healthy vitamin D levels.
Research on this is ongoing, but the connection has been one science is keen to explore.
So, does vitamin D have an effect on the severity of asthma attacks?
The researchers looked for asthma attacks in the data, defined as attacks needing treatment with steroid pills, as well as tracking things like emergency hospital visits, lung tests and asthma symptoms if they were reported in a daily fashion. After two researchers independently assessed the quality of studies (thereby trying to reduce bias in the studies themselves and the selection criteria), the researchers also used standard statistical methods to calculate an overall risk of asthma attacks occurring with vitamin D supplementation and without.
What the researchers found was that people taking vitamin D supplements reduced their risk of severe asthma attacks that required hospitalization or an Emergency Room visit by three percent. The researchers also found that the rate of people needing steroid treatment for their attacks over the course of a year went from 0.44 to 0.28 per person. There was no apparent effect on long function tests or general day-to-day asthma symptoms though.
It might seem like this effect is only slight, but the researchers say that the findings are encouraging as they may offer a relatively cheap way for asthma sufferers to cut the risks of more severe attacks through simple vitamin D supplementation. They did however caution that the results must be taken in context and that it’s too early to say whether this effect can be generalized.
“The effect we saw was restricted to prevention of severe asthma attacks, so asthma patients who do not get such attacks (around 50% of asthma patients) will not get a benefit from vitamin D in terms of their day-to-day symptoms,” researcher Adrian Martineau from the Asthma UK Centre for Applied Research at Queen Mary University of London is quoted as saying.
The researchers readily acknowledge a number of limitations to this study, too. For one thing, not all asthmatics are vitamin D deficient and so researchers can’t be sure the effect would be as pronounced on people who already have an ample supply of vitamin D.
Furthermore, the studies looked at in this analysis involved adults with mild to moderate asthma symptoms and only a relatively small number of children were included. As such, more testing will need to be done to see if there’s a similar effect for people with more severe asthma symptoms and also for young sufferers. Researchers are now looking into those issues further.
A number of health bodies have recommended vitamin D supplementation due to the fact that the general population working in offices and staying inside for greater periods of time rarely get enough sunlight to produce an adequate amount of vitamin D. In fact, Public Health England recently recommended the general population supplement their vitamin D levels during the autumn and winter months. Vitamin D is seen as a relatively low cost way of improving bone and muscle health, and while complications can occur from over supplementation–high doses may cause some health problems–it is generally agreed to be among the safer supplements for the general population.
To be clear, no one is suggesting that vitamin D is going to completely cure asthma symptoms, but in a field where breakthroughs in asthma treatments have been frustratingly slow, the potential benefit of vitamin D supplementation is encouraging and may, for some sufferers, perhaps be a ray of light on the horizon.
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