Factors associated with vitamin/mineral supplement use by Canadians

Transcription

1 Factors associated with vitamin/mineral supplement use by Canadians Hassan Vatanparast, MD, PhD Assistant Professor, School of Public Health & College of Pharmacy and Nutrition, Susan Whiting, PhD Professor, College of Pharmacy & Nutrition 1

2 What Is Dietary Supplement? A dietary supplement is a product that is intended to supplement the diet; contain one or more dietary ingredients (including vitamins, minerals, herbs, other botanicals, amino acids & other substances) or their constituents; is intended to be taken by mouth as a pill, capsule, tablet, or liquid; and is labelled on the front panel as being a dietary supplement Dietary Supplement Health and Education Act (DSHEA)- USA 2

3 Why we should assess dietary supplement intake? Evaluate total intake of nutrients Assess risk of toxicities Assess nutrient nutrient & nutrient drug interactions Clarify associations between dietary supplement intake & health status Assess conformity with health promotion & disease prevention recommendations & guidelines Dwyer Y & Costello RB in Coulston & Boushey,

4 What we know about supplement use in Canada Regulating body: Natural Health Products (NHP), Health Canada 71% of Canadians have used NHP 46% believe unproven claims by companies 37% : too expensive 52%: not enough info on label 52%: Health Canada does not do a good job by informing Canadians about NHP 47% trust doctors, pharmacist (43%), Health Canada (34%), registered dietitian (30%) 4

5 Prevalence of dietary supplement use USA: has increased since 1994 Adults roughly 50%, very high among elders, high among young children (~ 30%) Positive association between supplement use, income & educational status High among those in poor health status Canada: No nationally representative comprehensive data on supplement use, nutritional status & related factors before Canadian Community Health Survey Cycle 2.2, 2004, (CCHS 2.2) Picciano et al. 2007, Radimer et al. 2004

6 Components of Supplement Study at the U of S LITERATURE REVIEW Risks and benefits of supplements Effect of income on supplement use QUANTITATIVE Determine key problem nutrients using CCHS Determine factors for supplement use in Canada QUALITATIVE Key informants on clients needs Focus groups of target groups Community consultation regarding next steps Supplement costing

7 Research objectives To characterize vitamin/mineral intake of Canadians in all age/sex groups To examine factors affecting the use of supplement intake among Canadians To determine the contribution of calcium supplement to overall calcium intake 7

8 CCHS Cycle 2.2, Focus on Nutrition Participants: 35,107, population aged 0+ Representative at national (excluding territories) & provincial levels Three stage release: July 2005 July 2006 April 2008: detailed information on supplement intake Two main components General Health (Vitamin & Mineral Supplements) 24 h recall (Food & Nutrient Intake data) 8

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10 Percent supplement consumers by age group (Canada( Canada) Both sexes Females Males

11 Percent supplement consumers by province (All age groups) Both sexes Females Males

12 Canadian adults using supplement by income categories middle income Upper middle income Highest income 12

13 Canadian adults using supplement by 2 education categories graduate & higher * * * * 13

14 Canadian adults using supplement by food security status 14

15 Mean intake of calcium (mg/d) from food in calcium supplement users/non users mg/d 15

16 Weighted Logistic regression, outcome: supplement use Variables Odds Ratio p value Age, (1 8 y, indicator, 40% supplement user) 9 18 y, Males 0.59 < y, Females 0.62 < y, Males 0.41 < y, Females & Over, Males & Over, Females 1.7 <

17 Logistic regression, outcome: supplement use Variables Odds Ratio p value Sex 1.8 (female) < Chronic conditions 0.85 (w/o) Education 1.4 (secondary grad. & more) < Income Indicator: Lowest Lower Middle Upper Middle Highest income 1.6 < Food security Indicator: food secure Low hunger Moderate hunger Severe hunger

18 Discussion Proportion of females who took supplements was higher than males in all age groups over 13 y & increased by age, income (in most age groups), education (completing secondary school) food security Mean intakes of calcium from food was similar among supplement users & non users. supplements are less likely taken by those who are at need.

19 Discussion... Agreement with the US NHANES data: low income, food insecurity, and low education are barriers to supplement use. Radimer et al The prevalence of inadequacy in nutrient intake is greater in food insecure adults Kirkpatrick & Tarasuk, 2008, CCHS data Our finding that food insecure adults were less likely to take supplements indicate the high nutritional vulnerability of food insecure individuals. A need to address potential health disparities with unequal access to vitamin/mineral supplementation.

20 Confusion in choosing supplement One of our interviewees in focus group I think we get a lot of information from magazines and the ads on TV and everything and we are not quite sure what is right. 20

21 Acknowledgement Canadian Foundation for Dietetic Research Contact 6/23/

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23 Benefits of nutrients beyond prevention of deficiency Nutrient(s) NIH report (2007) Various micronutrient (antioxidants) cancer mortality, macular degeneration Our review (most recent papers) risk of pediatric brain Multivitamin tumours, neuroblastoma & Leukemia Vitamin E risk of nuclear cataracts risk of prostate cancer, CVD Selenium liver cancer, skin cancer cancer incidence in men, mortality cancer mortality Folic acid neural tube defects risk of stroke Vitamin D & calcium non vertebral Fx in postmenopausal women risk of fall (vitamin D) Magnesium Type II diabetes National Institute of Health 23

24 Percent supplement consumers by age group (Manitoba) Both sexes Females Males

25 Need for a reliable source American Dietetic Association,

26 Distribution of supplement use in Canadians by chronic conditions 26

27 % meeting adequate intakes (AI) for calcium, Canada, 2004 Males Females

28 Methods Data were merged from different files to create the dataset of interest Various variables were created from the original variables relative to the research questions The modified version of SIDE IML was used to determine usual intake of calcium from Food (first round) Food & supplement (2 nd round) 28

29 Methods... Sampling weights: to obtain unbiased estimates of population quantities in all analyses Bootstrap method, to estimate standard errors, coefficients of variation & confidence intervals for populations. Bootstrapped confidence intervals (CI): to investigate difference between groups Logistic regression: outcome= supplement use including related factors into the model Statistics Canada Guide for CCHS 29