Vitamin and mineral supplement consumption in Canada: do users differ from non‐users in terms of nutrient adequacy and risk of high intakes?

Abstract

While the use of vitamin/mineral supplements is common in Canada, reaching over 60% in some sex/age groups, there is little information on the diet quality of supplement users compared to non-users. We used the nationally-representative Canadian Community Health Survey 2.2 (n = 35,107) to i) compare the prevalence of inadequacy and percent of intakes above the Tolerable Upper Intake Level (UL) of vitamins and minerals from food intake among users and non-users of supplements; and ii) investigate the impact of supplements on the diet quality of users. Children 1 to 8 years had no prevalence of nutrient inadequacy irrespective of supplement use. Except for vitamin A (40% inadequacy) and magnesium (45% inadequacy), there was very little nutrient inadequacy among adults, and users did not differ from non-users. There was no risk of excessive intakes from food alone among users or non-users, except for zinc in children. When supplement intake was included, the percent of intakes above the UL in users rose considerably for vitamins A, C, niacin, folic acid, iron, zinc and magnesium, reaching as high as 70% for zinc in children. In sum, for most nutrients investigated, supplement use is largely unnecessary. In fact, supplement use is mainly responsible for excessive intakes of several nutrients. There is a need for further evaluation of the risks and benefits of supplement use in light of Canadians' nutrient intakes from food. Grant Funding Source: Canadian Institutes of Health Research