Lay opinion vs evidence: Magnesium Labor

Magnesium lab testing: lay opinion vs evidence. Many believe a simple blood test reliably detects magnesium deficiency. In reality, serum magnesium reflects only <1% of total body stores and only drops in severe deficiency. Intracellular magnesium (e.g., in whole blood or RBC) is more informative but not standardized. Without clinical symptoms or risk factors (e.g., diabetes, diuretics), a magnesium lab often has limited utility. Evidence is moderate: testing can help when deficiency is suspected, but overinterpretation and unnecessary supplementation are common. MyBody-X does not offer a specific magnesium test; general nutrient tests are lifestyle tools, not diagnostics. Caveat: reference ranges vary, and a normal serum level does not rule out cellular deficiency. For symptoms like cramps or fatigue, medical evaluation is more appropriate than a home test.