Clinical Manifestations of Low Ferritin in Children Without Anemia

Iron deficiency remains one of the most prevalent nutritional deficiencies affecting children worldwide. Although anemia is commonly regarded as the primary consequence of iron deficiency, depletion of iron stores may occur long before hemoglobin concentrations decline below normal reference ranges. Low serum ferritin is recognized as an early indicator of reduced iron reserves and may be associated with a variety of clinical manifestations despite the absence of anemia. Increasing evidence suggests that iron deficiency without anemia is not merely a laboratory finding but a condition with potential implications for multiple physiological systems during critical stages of growth and development. Iron plays a central role in numerous biological processes, including oxygen transport, cellular energy metabolism, neurotransmitter synthesis, myelination, immune function, and muscle activity. Consequently, inadequate iron availability may affect tissues with high metabolic demands even when erythropoiesis remains preserved. Children with low ferritin levels may present with neurocognitive and behavioral symptoms such as impaired attention, reduced concentration, learning difficulties, irritability, and hyperactivity. Associations between low ferritin concentrations and attention-deficit/hyperactivity disorder have also been reported. Physical manifestations may include fatigue, decreased exercise tolerance, reduced endurance, and diminished overall well-being. Sleep-related disturbances, particularly restless legs syndrome, periodic limb movements during sleep, and poor sleep quality, have likewise been linked to depleted iron stores. Recognition of low ferritin without anemia presents important diagnostic challenges because symptoms are often nonspecific and may overlap with other pediatric conditions. Serum ferritin remains the most widely used marker of iron stores; however, interpretation requires consideration of factors such as inflammation and infection that can influence ferritin concentrations. Current evidence highlights the importance of evaluating iron status beyond hemoglobin measurements alone, particularly in symptomatic children and those with recognized risk factors for iron deficiency. Improved awareness of the clinical significance of low ferritin may support earlier identification of affected children, facilitate appropriate management, and help prevent progression to overt iron deficiency anemia while minimizing potential impacts on health, development, and quality of life.