Abstract
PURPOSE: Adherence to vitamin supplementation recommendations after bariatric surgery is generally poor, which is associated with nutritional deficiencies. Patients' own perspectives and reasons for poor adherence to vitamin supplementation recommendations have not yet been studied in depth. The purpose of this study was first to measure the accuracy of self-reported adherence to supplementation recommendations by using objective measures of vitamin D levels in blood and thereafter to explore perceptions of barriers and facilitators to participants' adherence to supplementation recommendations. MATERIAL AND METHOD: Participants were recruited from a prospective study investigating the outcome of bariatric surgery in adolescents with severe obesity. Mixed methods were used, including a quantitative part where vitamin D levels were analysed through 25(OH)D levels in blood and/or a questionnaire on adherence to supplementation programmes 5 years after surgery (n = 40) plus a qualitative part with semi-structured interviews (n = 20). RESULTS: We found a convergence between self-reported adherence to vitamin supplementation and vitamin D 25(OH)D levels in blood indicating honestly in self-reported responses. The qualitative evaluations resulted in the categories awareness and personal capability and external factors. In the analysis, an overall theme emerged; capacity is crucial for adherence in youth who have undergone bariatric surgery. CONCLUSION: Bariatric surgery is a comprehensive procedure that requires lifelong treatment afterwards. There is coherence between what adolescents actually do and what they say they do. Capacity is crucial for adherence and social support has been shown to be important.