| The purpose of this study was to investigate Western and Eastern dietary supplement usage in Taiwan using a combination of constructs from different psychosocial and behavioral theories. This research was the first attempt of its kind in a Chinese society. It was a cross-sectional survey design study using convenience sampling to recruit study participants from a wide range of socio-economic statuses. A self-administered questionnaire was distributed to three companies to measure employees' dietary supplement usage, ten related psychosocial factors derived from the Health Belief Model, the Theory of Planned Behavior and Social Cognitive Theory, and one cultural health belief factor “bu,” meaning the use of tonics for nourishment.; Among 533 valid completed questionnaires (response rate = 77.8%), 37.5% reported taking only Western dietary supplements, 2.9% taking only Eastern dietary supplements, 18.3% taking both, and 41.3% taking none. Western dietary supplements used most often included multivitamins (with and without minerals) (23.8%), vitamin C (20.0%), lactobacillus products (16.2%), while Eastern dietary supplements used most often included medicated diet (13.0%), ginseng (8.0%) and cordyceps (3.2%).; With regard to the relationships between psychosocial and cultural health belief variables and dietary supplement usage, discriminant function analyses showed that the most important psychosocial and cultural factor in determining whether or not people used Western dietary supplements (293 users vs. 232 nonusers) was social modeling (structure correlation = 0.80, p < .001), followed by perceived benefits (0.75, p < .001), cues to action (0.60, p < .001), overall health concern (0.58, p < .001), motivation to comply (0.52, p < .001), normative beliefs (0.50, p < .001), perceived severity (0.40, p < .01), “bu” (0.36, p < .01), and perceived susceptibility (0.31, p < .05). For Eastern dietary supplements (111 users vs. 414 nonusers), “bu” was the strongest differentiator (0.80, p < .001), followed by normative beliefs (0.51, p < .001), perceived benefits (0.49, p < .001), cues to action (0.37, p < .01), and overall health concern (0.33, p < .05).; To help prevent excessive and improper use of dietary supplements by the public, nutrition educators could address psychosocial and cultural factors underlining usage of different types of dietary supplements to facilitate the adoption of appropriate behavior. |
