Abstract
[Truncated] Background: Allergic diseases have reached epidemic proportions in Westernized countries over the last 30-40 years, with similar trends currently emerging in developing areas. The rapid rise in prevalence and coincidence with industrialisation indicates that changes in environment and lifestyle must be responsible. Identifying which environmental factors play a causal role in the development of allergic disease will be acrucial step in developing primary prevention strategies. Numerous causative factor shave been postulated by researchers, among which are changes in sun exposure and dietary patterns that dispose to a reduced vitamin D status in the population.
There are multiple lines of evidence to support a role of vitamin D in allergic disease including geographical variation in prevalence (corresponding to UV exposure), in vitro studies demonstrating immunomodulatory properties of vitamin D, and cohort studies reporting associations between vitamin D status and the presence or development ofallergic disease. Few of these studies, however, have utilized longitudinal study designs, combinations of immunological and clinical outcomes, or intervention in the form of randomized controlled trials. This PhD thesis aims to contribute to the scientific literature by investigating longitudinally the association between vitamin D status inearly infancy the development of allergic disease, in addition to testing the hypothesis that increasing the vitamin D status of infants through supplementation will result in a phenotypic immune profile representing a reduced risk of allergic disease.
Aims: The specific aims of this thesis are to: 1) describe the 25-hydroxyvitamin D(25[OH]D) status of pregnant women in Perth, Western Australia, in order to quantify the proportion of this population with suboptimal 25(OH)D levels, whilst identifying intrinsic and extrinsic factors associated with 25(OH)D status (Chapter 2); 2)investigate the relationship between 25(OH)D status at birth (cord blood) and in infancy (6 months of age) in relation to risk of clinical allergic disease in infancy and childhood (Chapters 3 and 4); and 3) identify differences in infant immune phenotype between participants stratified by vitamin D supplementation, 25(OH)D status and UV exposure(Chapter 6).
There are multiple lines of evidence to support a role of vitamin D in allergic disease including geographical variation in prevalence (corresponding to UV exposure), in vitro studies demonstrating immunomodulatory properties of vitamin D, and cohort studies reporting associations between vitamin D status and the presence or development ofallergic disease. Few of these studies, however, have utilized longitudinal study designs, combinations of immunological and clinical outcomes, or intervention in the form of randomized controlled trials. This PhD thesis aims to contribute to the scientific literature by investigating longitudinally the association between vitamin D status inearly infancy the development of allergic disease, in addition to testing the hypothesis that increasing the vitamin D status of infants through supplementation will result in a phenotypic immune profile representing a reduced risk of allergic disease.
Aims: The specific aims of this thesis are to: 1) describe the 25-hydroxyvitamin D(25[OH]D) status of pregnant women in Perth, Western Australia, in order to quantify the proportion of this population with suboptimal 25(OH)D levels, whilst identifying intrinsic and extrinsic factors associated with 25(OH)D status (Chapter 2); 2)investigate the relationship between 25(OH)D status at birth (cord blood) and in infancy (6 months of age) in relation to risk of clinical allergic disease in infancy and childhood (Chapters 3 and 4); and 3) identify differences in infant immune phenotype between participants stratified by vitamin D supplementation, 25(OH)D status and UV exposure(Chapter 6).
| Original language | English |
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| Qualification | Doctor of Philosophy |
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| Publication status | Unpublished - 2015 |