What to watch with Ferritin and Schlaf?

Ferritin and sleep are connected through several pathways, though the provided context does not directly link them. Ferritin is the primary marker for body iron stores. Low ferritin (<30 ng/mL) indicates iron deficiency, which is strongly associated with Restless Legs Syndrome (RLS), a common cause of sleep disruption. Clinical evidence shows that iron supplementation in RLS patients with low ferritin can improve sleep quality. However, ferritin is also an acute-phase reactant: during inflammation or infection, levels rise even when iron stores are depleted. This inflammatory elevation can itself disturb sleep via cytokines that alter sleep architecture. The context also mentions the CLOCK gene (rs1801260) affecting chronotype, but that is a separate mechanism. For reliable interpretation, ferritin should be assessed alongside CRP, transferrin saturation, and possibly hepcidin to rule out inflammation. Without this differentiation, a normal ferritin value during inflammation may mask iron-deficiency-related sleep problems. The evidence linking ferritin to sleep is clinically and mechanistically sound, but not directly supported by the provided sources.