Combining nutrient intake from food/beverages and vitamin/mineral supplements.
BACKGROUND
To calculate total intake of a nutrient and estimate inadequate intake for a population, the amounts derived from food/beverages and from vitamin/mineral supplements must be combined. The two methods Statistics Canada has suggested present problems of interpretation.


METHODS
Data collected from 34,386 respondents to the 2004 Canadian Community Health Survey-Nutrition were used to compare four methods of combining nutrient intake from food/beverages and vitamin/mineral supplements: adding average intake from supplements to the 24-hour food/beverage recall and estimating the usual distribution in the population (Method 1); estimating usual individual intake from food? beverages and adding intake from supplements (Method 2); and dividing the population into supplement users and non-users and applying Method 1 or Method 2 and combining the estimates based on the percentages of users and non-users (Methods 3 and 4).


RESULTS
Interpretation problems arise with Methods 1 and 2; for example, the percentage of the population with inadequate intake of vitamin C and folate equivalents falls outside the expected minimum-maximum range. These interpretation problems are not observed with Methods 3 and 4.


CONCLUSIONS
Interpretation problems that may arise in combining food and supplement intake of a given nutrient are overcome if the population is divided into supplement users and non-users before Method 1 or Method 2 is applied.
Health Analysis Division at Statistics Canada, Ottawa, Ontario K1A 0T6. Didier.Garriguet@statcan.gc.ca
Didier
D
Garriguet
D000293:Adolescent; D000328:Adult; D000368:Aged; D001628:Beverages / Q000706:statistics & numerical data*; D002170:Canada; D002648:Child; D002675:Child, Preschool; D003625:Data Collection / Q000379:methods; D004032:Diet; D019587:Dietary Supplements / Q000706:statistics & numerical data*; D005260:Female; D005502:Food / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D008297:Male; D011939:Mental Recall; D008903:Minerals / Q000008:administration & dosage*; D009749:Nutrition Surveys; D057566:Self Report; D014815:Vitamins / Q000008:administration & dosage*; D055815:Young Adult
D008903:Minerals; D014815:Vitamins