Publication Date


Document Type


First Advisor

Parham, Ellen S.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Human and Family Resources


Vitamins in human nutrition; Minerals in human nutrition; Dietary supplements; Nutrition--Psychological aspects; Health attitudes


This study was designed to explore the relationship of beliefs in the efficacy of vitamin, mineral and other nutritional supplements and self-rated health status to the range of supplement use. A questionnaire was developed to yield quantitative scores for the strength of beliefs in the efficacy of supplement use (the Beliefs Instrument), perception of quality of health (the Perceived Health Instrument), and intensity of supplement use (the Intensity of Supplement Use Instrument). The questionnaire was distributed by convenience sampling methods to 85 individuals previously identified as heavy users of nutritional supplements and by systematic probability sampling to 409 members of the faculty and staff at Northern Illinois University. Each of the 305 returned questionnaires suitable for analysis were classified as either nonusers, light or heavy users of nutritional supplements. To equalize the representation of user groups, 60 questionnaires were randomly selected from each of the three user groups to test the hypothesis that mean scores for the Beliefs Instrument and the Perceived Health Instrument would be different for the three user groups. Mean scores of the user groups were significantly different for both instruments, as determined by one-way ANOVA and Duncan procedure, supporting the hypothesis that nonusers, light users and heavy users of nutritional supplements have different beliefs about the efficacy of supplement use and differ in their perceptions of self- rated quality of health. Subscales within the Beliefs Instrument, designed to test differences between user groups for specific beliefs, showed significant differences between all three user groups for all of the subscales except therapeutic and ergogenic use. It appears that only heavy users believe in the use of supplements as therapeutic agents and to enhance athletic performance. Subscales within the Perceived Health Instrument found differences in attitudes about their health between user groups. Users, especially heavy users, were more involved in personal health outcomes, more positive about their present and future health status, and more reluctant to accept illness or see a doctor. Users also had higher scores for perception of health status and were more likely to report improved health as supplement use increased. Both light and heavy users who reported chronic illness had higher scores for Current Health and Change in Health subscales than nonusers .


Includes bibliographical references (pages [53]-58)


vii, 136 pages




Northern Illinois University

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