What role does Magnesium play in fatigue?

Magnesium is an essential mineral involved in over 300 enzymatic reactions, including ATP production, muscle contraction, and nerve function. A deficiency can theoretically contribute to fatigue. However, the evidence for a direct causal role is mixed: observational studies show associations between low magnesium and increased tiredness, but robust randomized controlled trials demonstrating that supplementation improves fatigue in non-deficient individuals are lacking. In conditions like chronic stress, poor sleep, or muscle cramps, optimizing magnesium status may help, but effects are often modest and individual. Caution is needed in kidney disease or with certain medications. Serum magnesium only reflects ~1% of body stores; functional tests are more informative. Overall, magnesium is a supportive factor, not a cure-all for fatigue.