Can systemic inflammation lower serum zinc without true zinc loss?

Systemic inflammation initiates a profound systemic realignment of micronutrient trafficking as part of the acute-phase response. During this process, circulating serum zinc levels can drop precipitously, mimicking a nutritional deficiency even when total-body zinc stores remain completely adequate.

Molecular mechanisms of redistribution

• Cytokine signaling: Inflammatory stimuli (such as lipopolysaccharides, sepsis, or acute stress) trigger the rapid release of Interleukin-6 (IL-6), which acts as a master transcriptional regulator.
• Transporter upregulation: IL-6 directly upregulates the expression of the zinc importer ZIP14 (SLC39A14) on the membranes of hepatocytes.
• Intracellular sequestration: Concurrently, IL-6 induces the transcription of metallothioneins (MT1/MT2). These proteins act as high-affinity intracellular zinc sinks, sequestering the imported zinc within the liver to support cellular signaling and acute-phase protein synthesis.

Diagnostic implications

• False-positive deficiency: Because this active, cytokine-driven compartmental shift rapidly pulls zinc out of the bloodstream and into tissues, plasma or serum zinc levels drop independently of nutritional status.
• Biomarker confounding: Interpreting depressed circulating zinc as a dietary deficiency during periods of elevated inflammation (indicated by high C-reactive protein or IL-6) can lead to inaccurate clinical conclusions, as low serum zinc reflects active cellular sequestration rather than actual systemic depletion.

Bottom line

• Systemic inflammation actively drives zinc redistribution from plasma into tissues via the upregulation of the ZIP14 transporter and metallothioneins. This transient sequestration results in low serum zinc levels that reflect a cytokine-mediated compartmental shift rather than a true dietary or total-body zinc deficiency.