Vitamin supplementation in bariatric aftercare is essential to prevent nutrient deficiencies; however, rates of vitamin adherence have been as low as 30% 6months post-surgery. Preliminary literature suggests non-adherence to prescribed treatments can be linked to demographic and psychological factors. We aimed to determine the relationship between these factors to vitamin adherence in post-bariatric surgery patients. A total of 92 bariatric patients were assessed 6months post-surgery. Patients were administered a questionnaire collecting demographic information, psychological scores, and self-reported adherence. Nutrient deficiencies were analyzed through serum vitamin levels measured 3 and 6months after surgery. Wilcoxon rank-sum and chi-square tests were used for analysis. Non-adherence was associated with male sex and full-time employment (p=0.027, p=0.015). There were no differences with respect to living situation, education level, or relationship type. Non-adherent patients did not have significantly higher scores for generalized anxiety, depressive symptoms, or avoidant behaviors. However, non-adherent patients displayed greater attachment anxiety than their adherent counterparts (p=0.0186). Non-adherence was also associated with lower vitamin B12 levels 6months post-surgery (p=0.001). Male gender and full-time work have previously been shown to be associated with non-adherence. This is the first study to demonstrate that attachment anxiety is associated with poor multivitamin adherence in the post-surgical bariatric population. This result is concordant with recent literature that has demonstrated attachment anxiety is associated with poor adherence to dietary recommendations in bariatric patients 6months postoperatively. Presurgical screening for attachment anxiety could facilitate early interventions to promote better bariatric aftercare in this group.