As information regarding the details of dietary supplement use in Australia is lacking, researchers from the university sought to determine the prevalence and predictors of supplement intake within the Australian population.
Using data from the 2014 — 2015 National Health Survey, they assessed the prevalence of supplement use by age group and sex, followed by the independent predictors of supplement use in children, adolescents and adults.
They then found that 43.2% of adults (50.3% of females and 34.9% of males), 20.1% of adolescents (20.6% of females and 19.7% of males), and 23.5% of children (24.4% of males and 22.5% of females) had taken at least one dietary supplement in the two weeks prior to taking the survey.
Among the 19,257 survey participants, the most common type of dietary supplement was multi-vitamin and / or multi-mineral without herbal extracts, which was used by 17.5% of the population. The majority of such supplement users were between 30 and 49 years old (25.8% of women and 17.8% of men).
At the same time, 9.2% (9.8% of females and 8.5% of males) of the survey respondents used fish oil preparations without added nutrients, most of whom were aged 50 to 69 years old (16.1% of females and 13.2% of males).
Supplement use was generally higher among the female population, and among the adult survey participants, higher educated older women born outside Australia — and other mainly English-speaking countries — were more likely to use supplements. They also tended to be physically active non-smokers with healthy BMI.
The maximum number of supplements taken by any individual was 11 among adults, five among adolescents, and seven among children. Among adults, 50% of supplement users had taken more than one supplement in the previous two weeks.
The researchers observed that "the values are about twice those obtained in the 1995 Australian National Nutrition Survey, when 15% of adult males and 27% of females reported using dietary supplements in the previous 24 hours".
However, they added that the immediate reporting period of 24 hours, compared with two weeks in the current study, could explain the lower supplement use in 1995.
Furthermore, the current study's data showed that adult consumption of supplements was lower than in 2011 — 2012, where 52% of the adult population (58% of females and 45% of males) reported supplement use.
First and future implications
The researchers said that as far as they knew, this was "the first detailed investigation of dietary supplement use in a nationally representative sample of the Australian population".
They concluded: "Given that the use of multi-vitamins and / or multi-minerals and fish oil preparations is common in the Australian population, future studies investigating the contribution of supplements to overall dietary intakes of vitamins, minerals and omega-3 fatty acids are warranted."
"The Prevalence and Predictors of Dietary Supplement Use in the Australian Population"
Authors: Stacy K. O'Brien, et al.