Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.
Cramps, restless sleep, anxiety, glucose dysregulation. ~50% of US adults are below the EAR.
Most diets fall short; the average US intake is ~270 mg vs the 420 mg DV.
Daily target met. Supports 300+ enzymatic reactions, muscle relaxation, glucose handling.
Supplemental UL is 350 mg (separate from total diet). Stop or split doses smaller across the day.
You're at 0% of your magnesium target. The biggest single-serving sources to top it off:
Cofactor in more than 300 enzyme systems, including every ATP-using reaction (ATP must be bound to Mg2+ to be biologically active). Roughly half of US adults fail to meet RDA. Subclinical insufficiency is the modern norm because grain refining strips magnesium, and water softening removes it from drinking water.
Acts as a natural calcium channel blocker: magnesium occupies the NMDA receptor pore at rest, blunts L-type calcium channel activity, and stabilises cardiac and smooth muscle. Low Mg unmasks excess calcium signalling — explaining cramps, arrhythmias, vasoconstriction, and migraine susceptibility seen in deficiency.
Frank hypomagnesemia is uncommon in healthy adults but subclinical insufficiency is widespread — RBC magnesium is a more sensitive marker than serum. Conventional serum tests miss it.
UL of 350 mg/day applies only to supplemental magnesium (food magnesium has no UL). Excess from supplements causes osmotic diarrhea long before reaching toxicity. True hypermagnesemia is essentially limited to renal failure.
Glycinate, malate, citrate, and threonate are the well-absorbed forms. Avoid magnesium oxide and sulfate as the primary source — under 5% bioavailable, mostly laxative. Threonate has the strongest evidence for crossing the blood-brain barrier and is the niche pick for cognition; glycinate is the best general-purpose default.
Absorption ranges from <5% (oxide) to 30–40% (glycinate, citrate). Splits dose-dependently — 200 mg twice daily absorbs better than 400 mg once. High-dose calcium, zinc, and phytate reduce uptake. Active transport saturates; passive paracellular absorption takes over at higher doses.
Strong observational signal: higher dietary magnesium associates with lower all-cause mortality, cardiovascular events, and type 2 diabetes incidence. Adequacy supports insulin signalling, blood pressure regulation, and bone density — three of the biggest healthspan levers.
Cofactor for 300+ enzymes; sleep, muscle relaxation, ATP.
UL note: Applies to supplemental magnesium only (NIH ODS) — food magnesium is unrestricted, which is why the UL sits below the 420 mg DV.
Forms with lower absorption: oxide, sulfate. Prefer better-absorbed forms when supplementing.
The mechanisms and systems this nutrient feeds. Click any to drill into what runs on it.
★ = load-bearing / primary cofactor. Track these in My Journey.
Whole foods that contribute meaningfully (≥10% DV per 100 g serving). Click any food to see its full nutrient profile and what else it brings to the table.
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