Is Ferritin useful for sleep?

Ferritin is a protein that stores iron and is commonly used as a biomarker for body iron levels. Low ferritin indicates iron deficiency, which is strongly linked to restless legs syndrome (RLS) – a condition that causes uncomfortable leg sensations and an urge to move, especially at night, severely disrupting sleep. Clinical evidence shows that iron supplementation in deficient individuals can reduce RLS symptoms and improve sleep quality. However, ferritin is not a direct sleep biomarker; sleep is influenced by many factors including stress, hormones, and sleep hygiene. High ferritin (iron overload) can also cause health issues like liver damage and potentially affect sleep. The evidence for ferritin's usefulness specifically for sleep is moderate, based on observational and interventional studies on RLS. A ferritin test can be part of a medical workup for sleep complaints, but it should not be used alone to assess sleep health. Without clinical context and physician interpretation, its value is limited. Caveat: Do not self-supplement iron without confirmed deficiency and medical advice.