Abstrak: Observational studies suggest that people with a high serum 25-hydroxyvitamin D (25(OH)D) concentration may have reduced risk of chronic diseases such as osteoporosis, multiple sclerosis, type 1 diabetes, cardiovascular disease, and some cancers. The AusD Study (A Quantitative Assessment of Solar UV Exposure for Vitamin D Synthesis in Australian Adults) was conducted to clarify the relationships between ultraviolet (UV) radiation exposure, dietary intake of vitamin D, and serum 25(OH)D concentration among Australian adults residing in Townsville (19.3°S), Brisbane (27.5°S), Canberra (35.3°S), and Hobart (42.8°S). Participants aged 18-75 years were recruited from the Australian Electoral Roll between 2009 and 2010. Measurements were made of height, weight, waist:hip ratio, skin, hair, and eye color, blood pressure, and grip strength. Participants completed a questionnaire on sun exposure and vitamin D intake, together with 10 days of personal UV dosimetry and an associated sun-exposure and physical-activity diary that was temporally linked to a blood test for measurement of 25(OH)D concentration. Ambient solar UV radiation was also monitored at all study sites. We collected comprehensive, high-quality data from 1,002 participants (459 males, 543 females) assessed simultaneously across a range of latitudes and through all seasons. Here we describe the scientific and methodological issues considered in designing the AusD Study.

Abstrak: Inconsistent evidence exists regarding the association between work-related factors and risk of multiple sclerosis (MS). We examined the association between occupational exposures and risk of a first clinical diagnosis of central nervous system demyelination (FCD), which is strongly associated with progression to MS, in a matched case-control study of 276 FCD cases and 538 controls conducted in Australia (2003-2006). Using a personal residence and work calendar, information on occupational history and exposure to chemicals and animals was collected through face-to-face interviews. Few case-control differences were noted. Fewer cases had worked as professionals (≥6 years) than controls (adjusted odds ratio (AOR) = 0.60, 95% confidence interval (CI): 0.37, 0.96). After further adjustment for number of children, cases were more likely to have ever been exposed to livestock than controls (AOR = 1.54, 95% CI: 1.03, 2.29). Among women, there was an increase in FCD risk associated with 10 or more years of exposure to livestock (AOR = 2.78, 95% CI: 1.22, 6.33) or 6 or more years of farming (AOR = 2.00, 95% CI: 1.23, 3.25; also adjusted for number of children). Similar findings were not evident among men. Thus, farming and exposure to livestock may be important factors in the development of FCD among women, with this finding further revealed after the confounding effect of parity or number of children is considered.