Researchers say African-American children and urban children who stay indoors a lot are most affected by asthma,a respiratory disorder.
Vitamin D may help ease asthma symptoms for obese children living in urban environments with high indoor air pollution.
Recent research from the Johns Hopkins University School of Medicine in Maryland found that having low levels of vitamin D was associated with respiratory problems from indoor air pollution in obese children in urban areas.
The researchers examined 120 children over a 9-month period in the Baltimore area. They tested the vitamin D levels in the blood of the children, their asthma symptoms, and the level of air pollution in their homes.
Of the 120 children involved in the research, all had preexisting asthma, and 1/3 were obese.
“Baltimore is one example where urban minority populations in the U.S. suffer disproportionately heavy burden of asthma. We know from our prior work that indoor air pollution is a significant contributing factor to asthma symptoms, especially among urban children who spend the majority of their time indoors,” Sonali Bose, MD, study author and assistant professor of medicine in the Division of Pulmonary, Critical Care and Sleep Medicine at the Icahn School of Medicine at Mount Sinai in New York, has said.
“There’s emerging scientific literature in support of the protective role of vitamin D in asthma, and therefore we wondered if low vitamin D levels in children with asthma might make them more vulnerable to the effects of indoor air pollution,” added Dr. Bose, who’s also on the adjunct faculty at Johns Hopkins. “By identifying individual risk factors, such as dietary factors, that may potentially be modifiable, we can begin to find ways to protect children from harmful effects of air pollution in the future.”
The researchers found that in homes with the highest levels of indoor air pollution, children who were obese and had higher blood vitamin D levels had fewer asthma-related symptoms.
Effects on African-American children
According to the U.S. Centers for Disease Control and Prevention, 6.1 million American children, or about 1 in 12 children, have asthma. Asthma disproportionately affects urban minorities, including African-American children.
Bose says the reasons behind the higher rates of asthma among African-American children remain a puzzle to researchers, but it is likely due to multiple reasons, including vitamin D deficiency.
“There are many factors that may contribute to the heavy burden of asthma in urban blacks, including but not limited to disproportionate exposures to environmental factors such as pollution, obesity, poor diet, genetics, and other yet-unidentified factors,” she said. “Vitamin D deficiency is also disproportionately present among black children, potentially due to a combination of poor diet and darker skin pigmentation, which blocks the production of vitamin D in comparison to lighter skin tones.”
In 2015, nearly 2.6 million non-hispanic blacks reported having asthma. In 2014, African-Americans were nearly three times more likely to die from complications due to asthma than their white counterparts.
African-American children were 10 times more likely than white children to die from complications due to asthma than those in the white population in 2015. Black children are also four times more likely to be admitted to a hospital due to asthma than white children.
Tonya Winders, president and chief executive officer of the Allergy and Asthma Network, says further research into why African-American children are disproportionately impacted by asthma is important.
“We truly do not fully understand if it is genetics, environment, or both that cause higher rates of asthma in children of color. It could be higher rates of pollution or allergens. It could also be lack of access to adequate healthcare or financial resources,” she said.