Recent reports from both Australia and the United States suggest that Vitamin D might play a role in the recent increase in allergic diseases, particularly food allergies. This study will utilise the Longitudinal Study of Australian Children to examine environmental risk factors of food allergy, their genetic predisposition to developing an allergy, and asthma in Australian children. Using indirect markers of food allergy status, such as prescription of hypoallergenic formula, EpiPen (Dey Pharma, Basking Ridge, NJ) prescription, and emergency department admission for probable food-induced anaphylaxis, it was surmised that the further a person resides from the equator, the more likely he or she is to have food allergy. It was further suggested that this could be related to UV exposure, with those cities with the lowest ambient UV radiation likely to have the highest proportion of the population with a Vitamin D insufficiency.
Australia is the prime country to examine these associations as its population has one of the highest prevalences of challenge-proved food allergy, eczema, and asthma. It also has one of the longest north-south borders in the world, measuring approximately 4,500 km from the North of Queensland to the South of Tasmania. Australia also has a nationally representative epidemiologic study, the Longitudinal Study of Australian Children (LSAC), containing information on 2 cohorts of children, parental reports of food allergy, eczema, and asthma, and potential confounders.
A further aim of this project is to examine how the relationship between mental health and asthma has changed in Australian generations and their different exposures throughout their lives. This will see the bringing together of a range of potential risk factors and confounders of asthma. In addition, the selection of cases of asthma in the cohort will be assessed by multiple routes to increase the validity of case selection, beyond existing self-diagnosis.
