21 ways that Magnesium is consumed by the body

Magnesium Table

Claude AI Sept 2026 Estimated prevalence, with the Route column rebuilt around what actually happens to the atom.

# Factor Route What it does ~% adults
1 Baseline ATP turnover Bound Nearly all ATP is active as Mg-ATP; ~600–800 enzymes bind Mg. Sets the size of the bound pool — consumes nothing 100%
2 Low dietary intake / refined food Not in Refining strips 80–95% of Mg; ~half of US adults below the EAR. The largest single driver ~50%
3 Chronic psychological stress Urine Catecholamines and cortisol drive renal wasting; low Mg then worsens stress reactivity ~50–70%
4 High sugar / refined carbohydrate Urine + Bound Glucose load and insulin raise urinary Mg; glycolysis also ties up Mg transiently ~50–60%
5 Caffeine Urine Mild transient diuresis. Real but trivial against a normal diet ~85% (small)
6 Excess sodium Urine Competes for tubular reabsorption ~90% exceed guidelines
7 Alcohol Urine Acute Mg diuretic — excretion rises 2–3× promptly; chronic use depletes brain, liver, muscle Romani 2008] [Rivlin 1994] ~55%
8 Aging (65+) Not in + Urine Lower fractional absorption, weaker renal conservation, more depleting drugs, lower intake ~all of that cohort
9 Insulin resistance / T2 diabetes Urine Hyperglycemic osmotic diuresis. Bidirectional — low Mg worsens insulin resistance ~35–45% incl. prediabetes
10 Exercise / sweating Sweat + Bound Sweat loss plus raised ATP turnover; matters most in heat and endurance work athletes, laborers
11 Diuretics (thiazide, loop) Urine Direct tubular wasting. One of the two biggest drug causes [Katopodis 2020] ~15–20%
12 Proton pump inhibitors Not in Raise luminal pH, cutting Mg solubility and TRPM6/7 transport; ~20% of long-term users hypomagnesemic [Gommers 2022] ~7–8%
13 High-dose calcium supplements Not in Competes at shared gut transporters; matters above ~1,000 mg/d with low Mg intake common in older women
14 Phytate / oxalate / phosphate Not in Bind Mg in the lumen. Cola phosphate is the more plausible one at real intakes diet-dependent
15 Metformin, insulin, β-agonists Shift Drive Mg intracellularly. Serum falls, body stores don't [Liamis 2021] ~10%
16 Estrogen / oral contraceptives Shift Redistributes to bone and soft tissue; serum only ~10% of women
17 Vitamin D repletion Sequestered (+ minor Urine) Not catalytic consumption. Mineralization deposits Mg into new bone with Ca — a one-time transfer during repletion. Raised Ca absorption can add modest CaSR-mediated renal wasting. Offset partly because 1,25(OH)₂D increases gut Mg absorption transient, during correction
18 Pregnancy & lactation Sequestered Fetal skeleton and milk draw on maternal stores ~3–4% at any time
19 GI disease & surgery Stool + Not in Celiac, Crohn's, chronic diarrhea, laxative abuse, bariatric bypass ~2–5%
20 Antibiotics (aminoglycosides, amphotericin B) Urine Direct tubular toxicity episodic
21 Calcineurin inhibitors (cyclosporine, tacrolimus) Urine Downregulate distal tubular TRPM6 transplant patients
22 Chemotherapy (cisplatin, carboplatin, cetuximab, panitumumab) Urine Severe wasting; EGFR inhibitors block the EGF signal TRPM6 needs. Largest per-person losses here oncology patients
23 Genetic tubulopathies (Gitelman, Bartter, TRPM6) Urine Lifelong severe wasting rare

Route legend

Route Meaning Body stores fall? Serum Mg falls?
Not in Never absorbed — low intake or blocked uptake Yes, gradually Late
Urine Filtered but not reabsorbed — true loss Yes Yes
Stool Unabsorbed plus secreted — true loss Yes Yes
Sweat True loss Yes Modest
Sequestered Moved into bone or new tissue, out of the exchangeable pool Exchangeable pool only Yes
Bound Complexed to ATP/substrate — cycles, nothing lost No Free Mg²⁺ only
Shift Moved intracellularly No Yes

The last two rows are the trap: they lower serum or free magnesium without removing a single atom from the body. Supplementing corrects the number but not the cause.

Related in VitaminDWiki

Calcium Magnesium ratio