Recently, published in the Journal of allergy and clinical immunology: practice, a study from Johns Hopkins University School of Medicine found that vitamin D may have a protective effect on asthmatic obese children living in urban environment with serious air pollution.
Dr. Kimberly gray, project director of the children's environmental health research center at the National Institute of environmental health, said the research team has identified many factors that make children in the inner city of Baltimore vulnerable to health problems caused by air pollution.
The study tested three factors - household air pollution levels, blood vitamin D levels and asthma symptoms. The subjects were 120 school-age children with asthma in Baltimore. One third of the study participants were obese.
The children were assessed at the beginning of the study and three more times over the next nine months.
Overall, the researchers found that low levels of vitamin D in the blood of obese children with asthma were associated with the harmful effects of indoor air pollution on the respiratory system. On the contrary, in families with more serious indoor air pollution, the higher the level of vitamin D in the blood, the less asthma symptoms of obese children.
More surprisingly, the researchers said, the results showed that the effect was more pronounced in obese children. This highlights a third key factor - the prevalence of obesity - and helps to uncover this risk when considering an individual's susceptibility to asthma.
Researchers say they will try to find ways to raise vitamin D levels in these children's blood to help them more resistant to the environment.
