HealthDay News — Updated evidence suggests that supplementation with vitamin D or its hydroxylated metabolites does not reduce the risk for asthma exacerbations, according to a study published online February 6 in the Cochrane Database of Systematic Reviews.
Anne Williamson, from the Queen Mary University of London, and colleagues examined the effectiveness and safety of administration of vitamin D or its hydroxylated metabolites for reducing the risk for asthma exacerbations and improving asthma symptom control in a review of trials. Twenty studies were included: 15 with 1155 children and five with 1070 adults.
The researchers found that the proportion of participants experiencing one or more asthma exacerbations treated with systemic corticosteroids was not affected by administration of vitamin D or its hydroxylated metabolites. Vitamin D supplementation also had no effect on the rate of exacerbations requiring systemic corticosteroids or the time to first exacerbation. No evidence of effect modification was seen by baseline vitamin D status, vitamin D dose, frequency of dosing regimen, or age.
“In contrast to our previous Cochrane review on this topic, this updated review does not find that vitamin D offers protection against asthma attacks or improves control of asthma symptoms,” a coauthor said in a statement. “However, the trials we looked at did not include many people with severe asthma or people with very low levels of vitamin D in their blood, so these are areas where more research is still needed.”
One author disclosed financial ties to the pharmaceutical industry.