Study Explores How Vitamin D May Mitigate Pollution-Linked Asthma Risks
December 18, 2024
A team of pediatric pulmonary medicine, asthma, and immunology experts, led by Franziska J. Rosser, MD, Yueh-Ying Han, PhD, and Juan C. Celedón, MD, DrPH from the Division of Pediatric Pulmonary Medicine at UPMC Children’s Hospital of Pittsburgh, has published new findings in the American Journal of Respiratory and Critical Care Medicine on the potential for vitamin D supplementation to reduce pollution-related asthma risks in children.
The Challenge: Pollution and Severe Asthma Exacerbations
Long-term exposure to fine particulate matter (PM2.5) has been linked to severe asthma exacerbations (SAEs) in children, particularly those with low vitamin D levels. Previous research indicated that children with asthma living near major roads faced nearly five times the risk of experiencing SAEs if their vitamin D levels were deficient. Despite this, few studies have examined whether supplementing vitamin D could help mitigate this environmental risk.
New Insights from the VDKA Trial
To explore this possibility, the research team conducted a post hoc analysis of data from the Vitamin D Kids Asthma (VDKA) Study, a double-blind, randomized, placebo-controlled trial conducted at four U.S. sites on which they published findings in JAMA in 2020. The study included children aged 6 to 16 with mild persistent asthma, vitamin D levels between 10 and 29 ng/mL, and a history of at least one prior SAE. Participants were randomized to receive either 4,000 IU/day of vitamin D3 or a placebo for 48 weeks. PM2.5 exposure was calculated using geocoded participant addresses and linked to high-resolution atmospheric pollution data.
Post Hoc Findings: Protective Effects of Vitamin D Observed
Data analysis from 75% of participants revealed a significant inverse relationship between vitamin D levels and PM2.5 exposure. Children in high-pollution areas who received vitamin D supplementation experienced reduced odds of SAEs and longer intervals between exacerbations. In contrast, no significant effect was observed in children living in low-PM2.5 environments.
"The protective effects of vitamin D supplementation were particularly notable in children exposed to higher levels of air pollution," says Dr. Celedón. "We believe these results show the importance of environmental and nutritional interventions in asthma management."
Implications for At-Risk Communities
The findings highlight a potential strategy for reducing asthma-related health disparities in communities disproportionately affected by air pollution. As Dr. Rosser and colleague’s write in the paper, the effect seen may arise as a result of vitamin D’s intrinsic anti-inflammatory and/or antioxidant properties, although the exact mechanisms are not known as this study was not designed to investigate this aspect.
"Pollution-related asthma risks are a significant public health challenge," says Dr. Rosser. "Our findings suggest that vitamin D supplementation could offer a low-cost, accessible intervention to support vulnerable populations."
Reference
Rosser FJ, Han Y-Y, Forno E, Guilbert TW, Bacharier WB, Phipatanakul W, Celedón JC. Vitamin D Supplementation, Long-Term PM2.5 Exposure, and Severe Asthma Exacerbations in Children With Low Vitamin D: A Post Hoc Analysis of a Double-Blind, Randomized, Placebo-Controlled Trial (VDKA). Am J Respir Crit Care Med. 2024 November 1. Online ahead of print.
Further Reading
Learn More About the Celedón Laboratory for Pediatric Asthma Research.
