Can Vitamin D Reduce Asthma Attack Risk?
Researchers say studies show the vitamin supplement can reduce the risk of asthma attack by 50 percent. Here’s why.
British researchers say they have found a way to cut in half the risk of asthma attacks that require hospitalization.
The answer is vitamin D.
The researchers from Queen Mary University of London concluded that taking oral vitamin D supplements in addition to standard asthma medication resulted in a 50 percent reduction in the risk of experiencing at least one asthma attack that required a visit to the emergency room.
Taking the vitamin supplement also led to a 30 percent reduction in the number of asthma attacks that required treatment with steroid tablets or injections.
“Vitamin D can boost immune responses to viruses that trigger asthma attacks, while simultaneously dampening down harmful inflammatory responses,” Adrian Martineau, PhD, a clinical professor of respiratory infection and immunity at Queen Mary University and a lead researcher on the study, told Healthline.
A serious ailment
According to the U.S. Centers for Disease Control and Prevention (CDC), more than 24 million people in the United States have asthma.
About 8 percent of American adults and 8 percent of children under 18 have from the condition.
An estimated 2 million visits to the emergency room result in a primary diagnosis of asthma.
In 2014, asthma led to 3,651 deaths in the United States. Globally, asthma accounts for 400,000 deaths annually.
Death from asthma typically occurs during a period of acute worsening of asthma symptoms.
“In a true asthma flare or attack, the airways become filled with mucus and the muscles contract. They can become plugged with mucus, cutting off all airflow, and ultimately may result in death if not treated,” Tonya Winders, president and chief executive officer of the Allergy and Asthma Network, told Healthline.
Help from vitamin D
Researchers hope use of vitamin D in addition to regular asthma medications will improve the quality of life for those living with asthma.
“This is yet another example of a growing body of data to suggest vitamin D supplements may help reduce asthma flares resulting in uncontrolled symptoms and significant impact of patients’ lives,” Winders said.
According to researchers, the impact from vitamin D is equivalent in size to that achieved through expensive antibody therapies.
“The fact that vitamin D is inexpensive and safe means that it is potentially a highly cost-effective intervention,” Martineau said.
Vitamin D can also be gained through sun exposure, though Martineau notes this carries a risk of skin cancer that supplements do not.
Additionally, depending on where you live in the world, sun exposure may not have sufficient ultraviolet B rays all year long to produce vitamin D in the skin.
The benefits of taking vitamin D supplements extend beyond asthma.
“In a nutshell, benefits for bone health [prevention of rickets, osteoporosis, and osteomalacia] and muscle health [prevention of falls] are pretty well accepted and noncontroversial. There is a strong body of evidence now that vitamin D supplementation can reduce risk of colds and flu, particularly in people who have low vitamin D levels to start,” Martineau said.
Taking a look at severe asthma
However, more work needs to be done for groups that were underrepresented in this study, such as children and adults with severe asthma.
More trials are ongoing, and within five years Martineau anticipates there will be more data.
“I would welcome additional data in severe asthma, where the burden is so high… Based on vitamin D’s safety record, it would be interesting to see its effects in children with asthma,” Winders said.
But the research only shows a benefit of vitamin D use in preventing asthma attacks, not in everyday symptoms.
“Around 50 percent of patients with asthma don’t suffer such attacks but are bothered by day-to-day symptoms. We have not shown a benefit of vitamin D on day-to-day asthma control,” Martineau said.
The number of asthma patients with uncontrolled symptoms is significant.
“[The disease in] over 50 percent of all asthma patients [is] not well-controlled, which results in symptoms like coughing, wheezing or shortness of breath. In fact, in a recent survey we found that over 80 percent of patients limited simple activities like household chores and exercise at least once per week due to asthma,” Winders said.
Martineau says there is enough evidence that would justify testing for vitamin D deficiency in asthma patients.
“I think the evidence is strong enough now to suggest that testing for vitamin D deficiency in people who have asthma attacks and treating it where it is found is likely to have a benefit in terms of reduced risk of colds and flu and reduced risk of asthma attack,” he said.