How are Magnesium and fatigue related?

Magnesium is an essential mineral involved in over 300 enzymatic reactions, including ATP production, muscle contraction, and nerve transmission. A deficiency can theoretically lead to fatigue. However, the evidence for a direct causal link between magnesium status and fatigue is primarily mechanistic and based on observational studies. Randomized controlled trials show fatigue improvement with supplementation only in individuals with confirmed magnesium deficiency. In people with normal serum levels, the benefit is unclear. Moreover, assessing magnesium status via blood or DNA tests (such as those offered by MyBody-X) has limitations: serum magnesium does not necessarily reflect intracellular stores, and genetic variants in magnesium metabolism usually have small effects. Safety note: High doses of magnesium (above 350 mg/day as supplement) can cause diarrhea and gastrointestinal discomfort; toxicity risk exists in renal insufficiency. Evidence: mechanistic, with moderate support from observational studies.