Celiac disease is a chronic autoimmune condition triggered by gluten ingestion in genetically predisposed individuals. The only effective treatment is strict, lifelong adherence to a gluten-free diet (GFD). While the GFD facilitates mucosal recovery and symptom resolution, ongoing complaints may persist even in patients who strictly comply with dietary guidelines. This review analyzes scientific literature published between 2015 and 2025 concerning selected nutrient deficiencies in individuals with celiac disease adhering to a GFD. Evidence indicates that individuals with celiac disease are at increased risk of deficiencies in dietary fiber, iron, zinc, magnesium, vitamin D, and B vitamins, especially folate and vitamin B12. These deficits are caused by multiple factors, including villous atrophy, impaired nutrient absorption, and the nutritional limitations of many processed gluten-free products. In some cases, deficiencies persist despite mucosal recovery and normalized antibody levels, which suggests ongoing subclinical malabsorption or inadequate dietary quality. Improving the nutritional adequacy of a GFD requires both education and strategic food selection. Naturally gluten-free foods—such as legumes, fruits, vegetables, and nuts—as well as fortified gluten-free products. Regular monitoring of nutritional status, including laboratory testing, is essential to prevent long-term complications. Supplementation may be necessary in clinically significant cases. Individualized, evidence-based dietary management remains key to optimizing health outcomes in individuals with celiac disease.