What to watch with Magnesium and fatigue?

Magnesium is often linked to fatigue because it plays a role in energy production (ATP synthesis). A deficiency can theoretically contribute to tiredness. However, the evidence is mixed: many people have normal serum magnesium levels but may still have a cellular deficit not captured by standard blood tests. Supplementation may help in cases of confirmed deficiency or subjective fatigue, but study results are inconsistent. Fatigue has many other causes (iron deficiency, sleep disorders, thyroid issues, stress). Genetic testing for magnesium transporters (e.g., TRPM6) or microbiome analysis (hints at absorption) are not clinically validated tools for diagnosing magnesium deficiency. Caution: excessive magnesium can cause diarrhea and heart rhythm problems. Recommendation: seek medical evaluation for persistent fatigue before supplementing. Evidence: practice/unclear.