Research Article: “At least i am doing something”: a health belief model-guided qualitative study of nutritional supplement use among cancer patients during treatment
Abstract:
Nutritional supplement use is widespread among people receiving cancer treatment, yet the motivations, belief structures, and lived experiences that shape these decisions are incompletely understood. This study applied the Health Belief Model (HBM) as a guiding theoretical framework to explore how and why adult cancer patients decide to use nutritional supplements during treatment.
A qualitative descriptive design was used. Twenty-five adults with pathologically confirmed malignant diagnoses participated in semi-structured interviews framed around the six core constructs of the HBM. Recruitment took place between August 2025 and January 2026. Data were analyzed using a hybrid deductive and inductive thematic approach. Reporting followed the 32-item Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist.
Four core themes and 10 sub-themes were identified: (1) seeking control in an uncertain world; (2) navigating a fragmented information landscape; (3) the body as a battleground, supplements as a tool for resilience; and (4) silent conversations, disclosure, distrust, and the patient–provider relationship. These themes mapped closely onto HBM constructs including perceived benefits, perceived barriers, cues to action, and self-efficacy. Participants described supplement use as a rational, experience-driven response to the physical and psychological pressures of cancer and its treatment, rather than as a rejection of conventional medicine.
The HBM provides a coherent lens for understanding supplement use behavior in cancer patients. The findings point to a substantial unmet need for non-judgmental, individualized nutritional guidance within oncology care. They support a shift toward collaborative, harm-reduction-oriented communication and better integration of qualified clinical nutrition professionals, such as registered dietitians or formally trained clinical nutritionists with oncology experience, into routine cancer care.
Introduction:
Nutritional supplement use is widespread among people receiving cancer treatment, yet the motivations, belief structures, and lived experiences that shape these decisions are incompletely understood. This study applied the Health Belief Model (HBM) as a guiding theoretical framework to explore how and why adult cancer patients decide to use nutritional supplements during treatment.
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