 Type 2 diabetes mellitus, T2DM, is a major health concern worldwide due to its high prevalence and associated morbidity and mortality. Obesity is a key risk factor for developing T2DM, but it can be prevented or treated through lifestyle modifications such as dietary changes. Vitamins have been suggested as a potential adjunctive therapy for obesity management, but their efficacy remains unclear. This review summarizes current evidence regarding the effects of vitamin supplementation on obesity and related metabolic parameters. The findings suggest that vitamin supplementation may reduce body weight, body mass index and fat mass, and improve insulin sensitivity and lipid profiles. However, further research is needed to confirm the effectiveness of vitamin supplementation in reducing obesity and its associated comorbidities.