Sun exposure is leading to food allergies getting more common in children as one goes further south in Australia, according to an expert.
Canberra-based allergy expert Dr Ray Mullins has constructed a national map of the allergy's incidence, which shows a clear trend of it being "more common in the south than it is in the north".
"We've now got evidence that low vitamin D levels are associated strongly with the risk of developing it," the Herald Sun quoted Mullins as telling AAP.
"The only thing that really came out was latitude, which is distance from the equator," he added.
The body's major source of vitamin D is exposure to sunlight and a lack of it is known to heighten a person's risk of multiple sclerosis, type 1 diabetes, cancer and even schizophrenia.
Mullins collected data from three sources to produce a map of the allergy in Australia, starting with 36,000 children Australia-wide who were prescribed special allergy-safe infant formula.
He also mapped the locations of 69,000 children prescribed an "EpiPen", emergency adrenaline to be used in case of a food allergy event.
Then he added the locations of 11,000 cases, over five years, of children who were rushed to hospital suffering an allergic reaction to food.
Considering factors that could skew the result, such as differences in population and access to doctors across the country, the study showed a significant clustering in Australia's south.
When it came to the difference between Cairns and Hobart, Mullins said incidences could be six times higher in the southern city.
"For EpiPens, there was a six-fold difference from far north to far south. For infant formula it was three times more common (in the south) and for (hospital) admissions it was roughly two-fold," said Mullins.
But he advised that the research should not be seen as encouragement for Australians to stop wearing sunscreen, as a person's required level of vitamin D could be obtained in just 20 minutes of mid-morning sun exposure.
The research is detailed in two papers published in the journals Pediatric Allergy and Immunology and the Annals of Allergy, Asthma and Immunology.