Can inflammation lower serum zinc and low zinc worsen immune inflammation?

Systemic inflammation and zinc homeostasis are bound in a complex, self-reinforcing pathological feedback loop. In older adults, understanding this bidirectional relationship is critical for addressing chronic, low-grade systemic inflammation.

Mechanistic pathways of zinc sequestration

• Cytokine-driven redistribution: During an inflammatory response, elevated pro-inflammatory cytokines—primarily interleukin-6 (IL-6)—upregulate the expression of the zinc transporter ZIP14 (Slc39a14) on hepatocyte membranes and increase hepatic metallothioneins (MT).
• Systemic depletion: This coordinated signaling cascade rapidly imports circulating zinc into hepatic tissue, causing inflammatory hypozincemia (low serum zinc) rather than representing a simple dietary deficiency.

Immune dysregulation and the reinforcing loop

• Loss of immune control: Depleted circulating zinc impairs thymic function, shifts the T-helper cell balance away from a Th1 response (reducing IL-2 and IFN-γ), and destabilizes regulatory T-cell (Treg) control by compromising FOXP3-dependent support.
• NF-kB hyperactivation: Intracellular zinc depletion removes the physiological brake on nuclear factor-kappa B (NF-kB) signaling. Uninhibited NF-kB translocates to the nucleus, promoting the transcription and overproduction of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6. This surge in cytokines feeds back to trigger further hepatic zinc sequestration, completing the reinforcing loop.

Bottom line

• Systemic inflammation drives zinc out of circulation and into the liver via IL-6 and ZIP14 upregulation. The resulting low serum zinc level removes the inhibitory brake on NF-kB signaling and impairs regulatory T-cell function, triggering an overproduction of pro-inflammatory cytokines that perpetuates and amplifies the inflammatory cycle. Clinicians should interpret low zinc levels alongside inflammatory markers like C-reactive protein (CRP) to distinguish active sequestration from nutritional deficiency.