Nutritional deficiencies, particularly in essential vitamins, play a critical yet often overlooked role in the treatment and recovery of pediatric oncology patients. As childhood cancer therapies, including chemotherapy and radiation, place immense stress on the body, the demand for proper nutrition increases. This review explores the prevalence and implications of vitamin deficiencies in pediatric cancer patients, focusing on vitamins D, A, C, E, and B-complex. These deficiencies can compromise immune function, delay healing, and reduce overall treatment efficacy, potentially impacting survival rates and long-term health outcomes. The article also examines how cancer treatments may exacerbate nutritional imbalances through malabsorption, anorexia, and increased metabolic needs. By reviewing current research, this article highlights the importance of early nutritional assessments and interventions, including targeted vitamin supplementation. Integrating these strategies into comprehensive cancer care may enhance recovery, improve quality of life, and optimize treatment outcomes for pediatric oncology patients. Future research directions are discussed, emphasizing personalized nutrition plans that address the unique needs of pediatric cancer patients.