Magnesium RBC

Intracellular magnesium - far more sensitive to deficiency than serum magnesium, which the body defends aggressively.

What Magnesium RBC Measures

Serum magnesium is tightly regulated - the body will cannibalize bone and intracellular stores to keep serum in range. This is why most people with real magnesium deficiency have normal serum levels. RBC magnesium reflects intracellular status and catches deficiency far earlier.

Magnesium is a cofactor in 300+ enzymatic reactions, including ATP synthesis, insulin signaling, and muscle contraction. Insufficient magnesium correlates with cramps, poor sleep, arrhythmia susceptibility, and insulin resistance.

What Affects This Biomarker

RBC magnesium is influenced by: dietary intake (dark leafy greens, nuts, seeds), GI absorption (alcohol, PPIs, and chronic diarrhea all reduce it), renal wasting (diuretics, some diabetes drugs), and supplementation (glycinate, malate, citrate are well absorbed; oxide is poorly absorbed).

In the Context of Peptide Protocols

Useful baseline marker for anyone with cramps, sleep issues, or metabolic syndrome. Retest 3 months after supplementation change. Oral magnesium supplementation at 300–400 mg elemental daily (glycinate or malate) is well tolerated.

Upload any lab PDF and MyProtocolStack maps your values to Magnesium RBC and 40+ other biomarkers. StackAI interprets the trend in context of your protocol.