Melatonin and Vitamins: A Promising Combination to Augment Conventional Anticancer Therapies

Cancer remains a major global health challenge, requiring new adjunctive therapies. Integrative oncology, which combines conventional treatments with complementary agents, has gained attention for improving patient outcomes. Melatonin, a potent antioxidant and immunomodulator, has shown promise in cancer therapy. Recent evidence suggests that combining melatonin with vitamins—particularly vitamin D, vitamin C, and vitamin E—may enhance its anticancer effects through synergistic mechanisms. Melatonin exerts anticancer effects by regulating oxidative stress, apoptosis, and immune responses. Vitamin D enhances immune modulation, while vitamins C and E provide antioxidant and cytoprotective benefits. Their combined action may improve tumor suppression and reduce treatment-induced toxicity. However, despite promising preclinical data, clinical studies on melatonin–vitamins synergy remain limited. This review explores the molecular interactions, current evidence, and research gaps in melatonin–vitamin combinations for cancer therapy. Future studies should focus on mechanistic insights, optimal dosing, and clinical trials to establish their role in integrative oncology. Unlocking this potential could enhance existing cancer treatment strategies and improve patient outcomes.