Published Online: November 29, 2016
In the United States, vitamin D insufficiency (a serum 25-hydroxy vitamin D level of <30 ng/mL) and asthma are common conditions among children and adults. Several studies have shown that vitamin D insufficiency is linked to asthma and its severity, but the evidence is inconclusive.
In an article in The Journal of Allergy and Clinical Immunology: In Practice, Han and colleagues analyzed data from a nationwide health survey conducted between 2001 and 2010, in order to examine the association of vitamin D insufficiency and current asthma or wheeze in 10,860 children (6-17 years) and 24,115 adults (18-79 years). The survey participants were asked if they had experienced any asthma symptoms such as wheeze or been diagnosed with asthma in the past year. A blood test determined Vitamin D levels.
Vitamin D insufficiency was common in both children (68%) and adults (76%). Han et al reported that children with vitamin D insufficiency were 1.4 times more likely to have asthma than children with adequate levels of vitamin D. Compared with adults with adequate vitamin D levels, those with vitamin D insufficiency were not more likely to have diagnosed asthma but were 1.2 times more likely to have had wheeze in the past year. Vitamin D insufficiency was also associated with lower lung function in both children and adults. The authors indicated that vitamin D insufficiency in the population decreased from 74% in 2001-2002 to approximately 65% in 2009-2010. During the same period, the prevalence (frequency) of asthma went down, from 8.2% between 2007 and 2008 to 7.3% between 2009 and 2010.
Studies are needed to determine whether and which groups of asthma patients should be routinely screened for vitamin D status. At this time; however, vitamin D cannot be recommended for asthma treatment, pending results from ongoing clinical trials.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.