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Background Despite the importance of folate in reducing the risk of Neural Tube Defects (NTDs) and the widespread introduction of mandatory folic acid fortification, there remains a lack of data on the sources where child bearing age women are obtaining their folate requirements. Objective We aimed to assess the folate status and dietary intake of folate in a sample of Australian women of childbearing age and to estimate the major contributors of folate intake. Methods Across-sectional study of forty-five (N=45) women (aged 18–47) conducted in Brisbane, Australia. Dietary intake of folate, assessed as Dietary Folate Equivalents (DFE’s) was measured via a validated food frequency questionnaire. Serum and red blood cell folate of participants were measured via commercial automated competitive binding assay. Results No participants were deficient in either serum or red blood cell folate, however, over one third of the group (n=16) did not consume an adequate intake of folate according to the Estimated Average Requirements (EAR). Meeting the EAR of dietary intake for folate was significantly associated with increased odds of having higher red blood cell folate status (OR=3.83;p=<0.05). Proportionally, folic acid fortified bread contributed 15.4% of total dietary folate intake. Conclusions Mandatory folic acid fortification provided a substantial proportion of the dietary folate intake in this sample. However, despite the mandatory fortification of bread making flour with folic acid a considerable proportion (36%) did not meet the estimated average requirement of dietary folate. Future studies should include females of childbearing age belonging to vulnerable populations, to elucidate the adequacy of folate intake in these groups and assess the impact of low intakes in these populations on blood folate status. Support or Funding Information David Borradale was supported via Queensland University of Technology’s Postgraduate Resea

This thesis is the first study to investigate the associations between sun exposure and folate degradation in a group of childbearing age women in a high UV environment. It examined whether the degree of sun exposure experienced by women influenced blood folate levels following a period of folic acid supplementation and found a strong significant relationship between increased sun exposure and folate degradation. This relationship has strong implications for public health and the thesis has provided a foundation for further research in this area.

Folate is essential for human health in the prevention of megaloblastic anaemia and neural tube birth defects as well as roles in cardiovascular disease and cancer. Therefore research into environmental factors that may impact folate status, such as solar ultraviolet radiation, is of great health significance. In vitro studies have shown that ultraviolet (UV) radiation can degrade folate and folic acid in human blood and this has been confirmed in several human studies. Despite these findings, there is a dearth of epidemiological research into investigating the relationship between folate status and the links to solar UV exposure.

Vitamin D is unique among the vitamins in that humans can synthesize it via the action of UV radiation upon the skin. This combined with its ability to act on specific target tissues via Vitamin D Receptor’s (VDR) make its classification as a steroid hormone more appropriate. While Vitamin D deficiency is a recognized problem in some northern latitude countries, recent studies have shown even in sunny countries such as Australia, vitamin D deficiency may be more prevalent than first thought. Vitamin D is most well known for its role in bone health, however, the discovery of VDR’s on a wide variety of tissue types has also opened up roles for vitamin D far beyond traditional bone health. These include possible associations with autoimmune diseases such as multiple sclerosis and inflammatory bowel diseases, cancer, cardiovascular diseases and muscle strength. Firstly, this paper presents an overview of the two sources of vitamin D: exposure to ultraviolet-B radiation and food sources of vitamin D, with particular focus on both Australian and international studies on dietary vitamin D intake and national fortification strategies. Secondly, the paper reviews recent epidemiological and experimental evidence linking vitamin D and its role in health and disease for the major conditions linked to suboptimal vitamin D, while identifying significant gaps in the research and possible future directions for research.

Vitamin D deficiency and insufficiency are now seen as a contemporary health problem in Australia with possible widespread health effects not limited to bone health1. Despite this, the Vitamin D status (measured as serum 25-hydroxyvitamin D (25(OH)D)) of ambulatory adults has been overlooked in this country. Serum 25(OH)D status is especially important among this group as studies have shown a link between Vitamin D and fall risk in older adults2. Limited data also exists on the contributions of sun exposure via ultraviolet radiation and dietary intake to serum 25(OH)D status in this population. The aims of this project were to assess the serum 25(OH)D status of a group of older ambulatory adults in South East Queensland, to assess the association between their serum 25(OH)D status and functional measures as possible indicators of fall risk, obtain data on the sources of Vitamin D in this population and assess whether this intake was related to serum 25(OH)D status and describe sun protection and exposure behaviors in this group and investigate whether a relationship existed between these and serum 25(OH)D status. The collection of this data assists in addressing key gaps identified in the literature with regard to this population group and their Vitamin D status in Australia. A representative convenience sample of participants (N=47) over 55 years of age was recruited for this cross-sectional, exploratory study which was undertaken in December 2007 in south-east Queensland (Brisbane and Sunshine coast). Participants were required to complete a sun exposure questionnaire in addition to a Calcium and Vitamin D food frequency questionnaire. Timed up and go and handgrip dynamometry tests were used to examine functional capacity. Serum 25(OH)D status and blood measures of Calcium, Phosphorus and Albumin were determined through blood tests. The Mean and Median serum 25-Hydroxyvitamin D (25(OH)D) for all participants in this study was 85.8nmol/L (Standard Deviation 29.7nmo