The results of the CRN consumer attitude survey suggest that consumers understand the supportive role dietary supplements can play in helping to ensure adequate nutrient intake and also understand that dietary supplements do not substitute for a good diet or a healthy lifestyle. Furthermore, the survey results suggest that consumers are aware that they should avoid over-consuming micronutrients by talking with their doctor if they are considering use of high dose single nutrient supplements.
The shortfalls in nutrient intake identified by large national surveys are widespread and are not small in magnitude. In the 2003–2006 National Health and Nutrition Examination Survey (NHANES), 93 % of respondents ages 2 years and older had intakes of vitamin D from food sources (naturally occurring and enriched/fortified foods) that were below the Estimated Average Requirement (EAR); 90 % were below the EAR for vitamin E; 45 % were below the EAR for vitamin A; 37 % were below the EAR for vitamin C, and 49 % were below the EAR for calcium . These low intakes need to be raised, and when the contributions from dietary supplements were considered they were in fact raised. In the same NHANES survey, the percentage of respondents who did not meet the EAR decreased by 11 to 30 % for the aforementioned micronutrients when all sources, including dietary supplements, were considered, in comparison to food sources only . These data demonstrate the efficacy of dietary supplement use in filling nutrient gaps. The CRN consumer attitude survey confirms that people understand that multivitamins and supplements of calcium and/or vitamin D can help fill nutrient gaps in the diet.
The NHANES 2003–2006 data also demonstrate that nutrient intake from fortification and dietary supplements does not present a meaningful risk for overconsumption. The percentage of the population with total intakes of most micronutrients greater than their respective Tolerable Upper Intake Levels (ULs) was very low. Combined intakes from foods, fortification, and supplementation resulted in less than 1 % of the population exceeding the UL for vitamin C, D, or E, while less than 3 % exceeded the UL for calcium . For vitamin A and folate, 1 or 2 % of the population exceeded the UL based on intakes from food and fortification alone, and the addition of supplementation increased this fraction to 5 or 6 % . The authors of this report note that the UL is defined as “the highest level of daily intake that is likely to pose no risk” and point out that “more research is needed on the adverse health effect, if any, from intake levels exceeding the UL” .
Long-term clinical trials support the safety of daily MVM supplementation. In the recent Physicians’ Health Study II, a trial of over 14,000 male physicians that took a daily MVM for over ten years, no serious adverse effects were found . Furthermore, a 2013 systematic review of available scientific evidence showed that supplementation with a MVM does not increase all-cause mortality, cancer incidence or mortality, or CVD incidence or mortality .
Use of multivitamins and other dietary supplements is prevalent among U.S. consumers and is associated with somewhat better nutrient intakes from diet alone and also with the adoption of other healthy lifestyle habits. Adult use of dietary supplements in NHANES 2003–2006 was 54 % overall but increased with age and was 58 % and 72 % in men and women, respectively, in the age range 51–70 . The Multiethnic Cohort Study also reported 58 % use in men and 72 % use in women in a sample of more than 100,000 healthy adults over the age of 45 . Interestingly, surveys show that dietary supplement use is just as prevalent among dietitians and other health professionals, including doctors and nurses, as among the general population [6, 15]. Users of dietary supplements tend to adopt other healthy habits including exercising, not smoking, avoiding obesity, and consuming somewhat better diets, leading the authors of the report on the Multiethnic Cohort to conclude that these findings “suggest that a ‘health conscious’ attitude predominates among dietary supplement users” . The CRN consumer attitude survey confirms that people understand that, while multivitamins and other dietary supplements can be beneficial in providing additional intakes of shortfall nutrients, they do not substitute for overall dietary improvement or the adoption of other healthy lifestyle habits. The CRN consumer attitude survey also indicates that people know they should talk to their doctor if they are considering using high dose, single nutrient supplements.
The top reasons given by consumers for using multivitamins and other dietary supplements focus on overall wellness. In NHANES 2007–2010, the most prevalent reasons given for using dietary supplements were to improve overall health (45 %) and to maintain health (33 %) . In a 2011 CRN consumer survey and a 2009 CRN survey of dietitians, the most prevalent reason given by consumers for using dietary supplements was overall health and wellness (58 %), while for dietitians overall health and wellness ranked second (53 %) behind bone health (58 %) [6, 15]. Consumers are, of course, also interested in disease prevention, but it is not the primary motivation given for using dietary supplements. The CRN consumer attitude survey confirms that people understand that multivitamins are not meant to cure disease or to be used as medicines.
The current survey data provide insight on consumer attitudes in the general adult population. However, a limitation of the survey is that it does not distinguish between the perceptions of dietary supplement users and those of non-users and does not stratify responses by demographic factors such as age. Future investigation into the potential variations in attitudes by age, gender, or other demographic factors may be desirable.
In the CRN consumer attitude survey reported here, respondents expressed perceptions consistent with the available evidence regarding the habits and motivations of dietary supplement users. They recognize the benefits of multivitamins and of calcium and/or vitamin D supplements in filling nutrient gaps and therefore improving health, but they also recognize that the use of dietary supplements does not replace the need to focus on overall dietary improvement and to adopt other healthy lifestyle habits.