A link between vitamin D deficiency and severe symptoms of allergic asthma has been shown in numerous studies. But scientists still don’t fully understand the vitamin’s role in reducing the body’s inflammatory response, and there has been some disagreement as to whether taking vitamin D supplements would actually have any impact on allergic asthma symptoms.
Now, a team of researchers from the Department of Molecular Pneumology at Universitätsklinikum Erlangen in Germany appears to have settled that debate. Their study, published in the March 24 edition of the Journal of Allergy and Clinical Immunology, found that children and adults who took vitamin D experienced less severe symptoms of allergic asthma and required fewer inhaled steroids.
The researchers recruited asthmatic and control groups of both preschool children (aged 4 to 6 years) and adults aged 18 to 65. After completing an intake questionnaire, the asthmatic groups were divided further into those who took vitamin D supplements and those who didn’t. Researchers also performed blood tests and lung function assessments.
After analyzing the data, the scientists discovered that children and adults who took vitamin D3 supplements had less pronounced asthma symptoms and fewer severe asthma attacks. They also required fewer doses from steroid inhalers. Furthermore, blood tests showed greater quantities of the protein (blimp-1) that is responsible for controlling the immune response of T helper cells in certain cells in the blood of people with higher levels of vitamin D3.
In order to better understand how vitamin D modulates the inflammatory response, researcher and doctoral candidate Janina Grund administered vitamin D to asthmatic mice. And once again, the vitamin led to less severe cases of asthma. The mice also had fewer allergy-inducing antibodies, and administering higher doses of vitamin D3 even triggered an anti-inflammatory reaction in their immune systems.
“Our results, taken together, indicate that supplementing food with VitD3 resulted in less severe clinical asthma manifestations in human studies as well as in a murine model of allergic asthma, indicating that VitD3 alters proinflammatory immune responses to anti-inflammatory immune responses in asthma,” the researchers wrote, concluding that it’s important for asthma sufferers to make sure they get enough of the vitamin.
While these results seem extremely promising, the team also noted that this was basic research, and more studies need to be done to make specific recommendations for possible treatments. “A larger cohort of asthmatic subjects would be needed in the future to extend our findings and to investigate if the VitD3 anti-inflammatory action is observed across the spectrum of asthma severity.”