Myths vs facts: Zink and fatigue

Zinc is often marketed as a cure for fatigue, but the evidence is mixed. True zinc deficiency (due to poor diet, malabsorption, or chronic illness) can cause fatigue, immune dysfunction, and hair loss; supplementation in such cases may improve energy. However, in the general population with adequate zinc levels, extra zinc does not reduce fatigue and may cause side effects like nausea and copper deficiency. Blood tests for zinc are unreliable due to homeostatic regulation; 24-hour urine or hair analysis may be more informative but are not standard. Direct-to-consumer DNA tests may report variants in zinc transporter genes (e.g., SLC30A8, SLC39A8), but these have small effect sizes and are not diagnostic. The myth that zinc alone boosts energy is not supported by robust evidence. For persistent fatigue, a comprehensive medical workup (iron, B12, thyroid, sleep, stress) is recommended.