Metabolic and bariatric surgery (MBS) is an effective intervention for severe obesity, but it carries a risk of nutritional complications that can adversely affect short- and long-term health outcomes. This chapter reviews the management strategies for these complications, emphasizing the need for comprehensive nutritional assessments and targeted interventions. Key points include the commonality of nutritional deficiencies post-MBS, with any single deficiency warranting a broad nutritional evaluation. Protein deficiency is particularly prevalent among patients undergoing diversionary procedures and vegetarians, necessitating careful monitoring of protein intake. Severe hypoalbuminemia requires hospital admission for intravenous nutrition and empirical supplementation. Iron deficiency anemia (IDA) is highlighted as the most common form of anemia in these patients, often complicated by multiple deficiencies and high hepcidin levels. Management includes thorough workups to rule out other causes and the administration of intravenous iron. Bone health emerges as a critical but often neglected area, with recommendations for routine screening and annual DEXA scans in postmenopausal women and symptomatic individuals. Lastly, neurological complications, although rare, are associated with significant morbidity due to their potential irreversibility. Early empirical treatment is advised for patients with neurological symptoms such as weakness, dizziness, and vision or gait disturbances. This chapter underscores the importance of vigilant, proactive management of nutritional status in post-MBS patients to prevent and mitigate these serious complications.