New study suggests that vitamin D levels protect against asthma symptoms associated with air pollution

New study published in The Journal of Allergy and Clinical Immunology: In Practice¹ suggests that vitamin D may protect against pollution-associated asthma symptoms in obese children. In the study, 120 obese children between the ages of 5 and 12 with physician-diagnosed asthma were evaluated at baseline, and every three months for nine months for levels of indoor fine particulate air pollution, serum vitamin D, and asthma symptoms. Results showed that subjects with low serum vitamin D levels had more adverse respiratory effects associated with indoor fine particulate air pollution. In homes with high levels indoor air pollution, high levels of serum vitamin D were associated with decreased symptom odds.

“It became very clear that African-Americans were at higher risk for vitamin D deficiency, particularly black children,” explained Sonali Bose, MD, the study’s lead author, of its conception. “We were also noticing a heavy burden of asthma in inner city minority children. It seemed as though vitamin D deficiency and asthma were coincident and interacting in some way.”

“What surprised us the most was that the findings of the study showed the effects were most pronounced among obese children,” Bose continued, in a press release. “This highlights a third factor at play here – the obesity epidemic – and helps bring that risk to light when considering individual susceptibility to asthma.”

Additional vitamin D may be obtained from more exposure to the sun and dietary supplements, but the sociological context may be a significant factor to consider as well. “Another important take home point is how the complex environment comes together to contribute to extra burden of asthma in these low-income, urban communities,” explained Nadia Hansel, MD, director of the Division of Pulmonary and Critical Care Medicine at Johns Hopkins, in a press release. “Our results suggest that improving the asthma burden in the community may require a multi-faceted approach.”
 

References:

Bose S et al. “Vitamin D status modifies the response to indoor particulate matter in obese urban children with asthma.” The Journal of Allergy and Clinical Immunology: In Practice, Published online ahead of print on February 11, 2019