Dietary supplement use in community dwelling older adults living in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand

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Background. The population within New Zealand and internationally is aging. Research from overseas suggests many older adults use dietary supplements (DS). The most recent data regarding DS use of older adults in New Zealand (NZ) was undertaken in 2008/2009 and found that 39.8% of males and 52.6% of females 51 to 70 years old were considered DS users. International research suggests there are associations between sociodemographic, lifestyle and health characteristics and DS use, however, in the NZ older adult population these are currently. Therefore, the aim of this study was to explore DS use in older community dwelling adults living in NZ. Methods. Community dwelling older adults aged 65 to 74 years and living in Auckland took part in this cross-sectional study. Data on DS use and sociodemographic, lifestyle and health characteristics was collected using a health and demographic questionnaire, a short international physical activity questionnaire, four-day estimated food record (4DFR), and anthropometric measurements. Chi-squared tests and independent t-tests were used to compare the characteristics of DS users versus non-DS users. Types of dietary supplements taken by female versus male DS users were also investigated using Chi-square tests. Results. Among the 371 participants (64.2% female; 93.5% European; mean age 69.7 ± 2.6), 64% were considered DS users. The most consumed DS was oil (25.9%), single vitamins (25.1%), single minerals (23.5%), and multivitamins (19.7%). Dietary supplement use was higher among females (70.6%) compared to males (52.6%) (p<.001). Most DS users took one (37%) or two (23.9%) supplements, with 15% taking five or more DS. Male DS users were significantly more likely to adhere to the Ministry of Health alcohol intake guidelines (p=.008), have a higher self-reported level of health (p=.016), and a higher Index of Multiple Deprivation (IMD) ranking compared to male non-DS users (p=.045). There was no significant difference in characteristics between DS users and non-DS users in females. Conclusion. DS use among older community dwelling adults living in NZ is high, and more common in females. In males, DS use was higher in those consuming alcohol within recommended guidelines, in those who had higher reported level of health, and those living with greater deprivation compared to male non-DS users. Further research on a more diverse and representative population group is required to better understand the DS use prevalence and predictors of use for the older adult population across NZ.