Evidence check: Zink in the context of fatigue

Zinc is an essential trace mineral involved in numerous enzymatic reactions, immune function, and cell division. Zinc deficiency can indeed cause fatigue, lethargy, and increased susceptibility to infections. However, the evidence for zinc supplementation improving fatigue in non-deficient individuals is weak. Most studies show benefits only in cases of confirmed deficiency or specific populations (e.g., chronic fatigue syndrome, elderly). For general fatigue without known deficiency, zinc supplementation is not evidence-based. Moreover, excessive zinc intake (e.g., >40 mg/day long-term) can be toxic and lead to copper deficiency. A blood test for zinc is available but has limited accuracy because serum levels do not always reflect total body stores. Anyone with persistent fatigue should first rule out other causes (iron deficiency, thyroid issues, sleep disorders, stress) with a doctor before considering zinc. Overall, the evidence for zinc in fatigue is moderate and context-dependent.