In what they say is one of the first studies to test the link, researchers are pointing to the vitamin folate as a potential way to help those suffering from allergies and asthma.

Johns Hopkins University researchers pored through more than 8,000 medical records, including those as young as toddlers or old enough to need walkers in order to gauge the levels of folate, sometimes known as vitamin B9, along with allergic and asthmatic responses.

By using the levels of allergy-caused inflammation, symptoms and folate levels, the scientists say they were able to correlate the vitamin with lower inflammation and reported symptoms.

"Our findings are a clear indication that folic acid may indeed help regulate immune response to allergens, and may reduce allergy and asthma symptoms," said lead investigator Dr Elizabeth Matsui.

The study cautions that the body of research has not yet been established to determine what amounts of supplementation would provide the most benefit.

Current federal dietary guidelines recommend 400 mcg of folic acid for adult men and women, although females who are pregnant are sometimes asked to have a higher vitamin intake for their child’s neurological health.