What Motivates Individuals To Take Vitamin And Mineral Supplements?

Nutrition Research Newsletter, August, 1999 by Marian L. Neuhouser, Ruth E. Patterson, Lisa Levy

Registered dietitians recommend obtaining nutrients through consumption of a varied diet. However, there has been much evidence showing that the use of vitamin and mineral supplementation is on the rise. Vitamin and mineral supplements may, in some instances, be helpful in reducing the risk of certain diseases. There are also some situations in which vitamin and mineral use can be detrimental, such as in the case of excessive intake of fat-soluble vitamins. Currently, little is know about the motivation of individuals consuming these supplements. A recent study was initiated by researchers at the Fred Hutchinson Cancer Research Center with the objective of describing motivations for the common use of vitamin and mineral supplements.

The data was collected as an ancillary study to the 1995-1996 Washington State Cancer Risk Behavior Survey, which was a random-digit-dial telephone survey of adults. The survey was developed to assess attitudes and behaviors associated with cancer risk and prevention. Subjects were eligible for this ancillary survey if they took vitamin or mineral supplements at least three times in one week. The subjects were administered a questionnaire about vitamin-supplement use over the phone and then attended a clinic appointment. At the clinic visit, subjects were asked to complete questionnaires concerning motivations for taking each of the supplements reported. For each different supplement taken, subjects were questioned about the source of information leading them to take the supplement, the main health reason for taking the supplement, and why they chose to receive this particular vitamin or mineral in the form of a supplement as opposed to through their diet.

Subjects had a mean age of 44 years, the overwhelming majority were white, and 56.7% were women. Multivitamins, vitamin C, and vitamin E were the most common supplements reportedly taken by this population. Approximately half of subjects taking multivitamins and vitamin C and one-third of those taking vitamin E reported initiating the supplements based on advice from family and friends. Greater than half of the calcium users began to take calcium supplements on the advice from a health professional such as a physician or dietitian. In general, multivitamins were reportedly taken in order to feel better. The main motivation for taking vitamin C was for the prevention of respiratory infections such as colds and flus. Reported reasons for taking vitamin E and calcium were to prevent chronic diseases. Almost half of the participants reported taking multivitamins because it was difficult to consume a balanced diet and therefore receive adequate nutrition. Users of vitamin E and C were likely to report that they believed it was impossible to obtain optimal amounts of the micronutrient through diet alone. Among the single-supplement users, 40-60% believed that even if they ate a well-balanced diet, it was not possible to obtain enough of the micronutrient solely through food. Approximately 40% of users of vitamin E felt that this vitamin would prevent heart disease and all of those participants taking calcium supplements believed that this mineral would prevent osteoporosis. Between 55% and 70% of subjects reported not knowing if vitamin and mineral supplements would be beneficial in the prevention of cancer.

These findings provide insight for health care professionals as to what motivates individuals to use supplemental vitamins and minerals. It is important to recognize that friends and families were the biggest influences when it came to deciding whether or not to use supplements. This information was not likely to be obtained from a health care professional. It is also interesting to note that a majority of individuals felt that they could not receive adequate micronutrients through diet alone, therefore ignoring the recommendations that a balanced diet is all that is needed. Health care professionals need to take these findings to heart and realize that it is important to discuss the use of vitamin and mineral supplements with their patients and clients.

Marian L. Neuhouser, Ruth E. Patterson, Lisa Levy, Motivations for using vitamin and mineral supplements, J Am Diet Assoc, 99(7): 851-853 (July 1999) [Correspondence: M. L. Neuhouser, Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., MP 702, Seattle, WA 98109-1024.]