Major minerals

Magnesium

300+ enzymes

Cofactor for 300+ enzymes; sleep, muscle relaxation, ATP.

Daily target

420 mg

FDA Daily Value

Upper limit

350 mg

Tolerable Upper Intake

Catalog matches

supplements in our catalog

Upper-limit caution

The Tolerable Upper Intake Level for Magnesium is 350 mg per day. Routine intakes above this level — counting food + supplements — raise the risk of adverse effects. Multivitamins, fortified foods, and standalone supplements stack faster than people expect.

What Magnesium does

Magnesium is a cofactor for over 300 enzymes — including every reaction that uses ATP (which is biologically active as Mg-ATP), DNA synthesis, and the Na/K-ATPase that maintains membrane potential. Roughly 50% of US adults consume below the EAR. Serum magnesium is poorly correlated with total body status because most magnesium is intracellular; RBC or 24-hour urine measurement gives a better picture. The unusual UL of 350 mg from supplements only (food is unrestricted) reflects that supplemental magnesium causes osmotic diarrhea well below toxic systemic levels.

Food sources of Magnesium

Approximate Magnesium content per serving. Whole-food intake counts toward your daily total alongside any supplemental dose.

Food	Serving	Magnesium
Pumpkin seeds (raw)	1 oz	150 mg
Almonds	1 oz	80 mg
Cooked spinach	1 cup	160 mg
Black beans (cooked)	1/2 cup	60 mg
Dark chocolate (70%+)	1 oz	65 mg
Avocado	1 medium	60 mg

Signs of Magnesium deficiency

●Muscle cramps, twitches, restless legs
●Fatigue, irritability, poor sleep quality
●Cardiac arrhythmias (palpitations, PVCs)
●Refractory hypocalcemia and hypokalemia (Mg is required for K and Ca handling)
●Migraine in some individuals

Who needs more Magnesium

Groups and situations where Magnesium requirements rise or status commonly runs low:

●Long-term PPI users (PPIs reduce intestinal magnesium absorption)
●Loop diuretics, thiazides — increase urinary magnesium loss
●Type 2 diabetes — magnesium is lost through glycosuria
●Alcohol use disorder, chronic diarrhea, IBD
●Endurance athletes with high sweat losses

Forms to avoid

Not all Magnesium forms absorb equally well. The following forms are commonly used because they're cheap, but their bioavailability is materially lower than alternatives — watch for them on supplement labels:

oxide
sulfate

Formulate's product scoring penalizes these forms when they appear as the primary Magnesium source — see the methodology page for the rubric.

How Magnesium appears on labels

Supplement labels list Magnesium under several names depending on the chemical form used. Any of these on an ingredients panel counts toward your Magnesium intake:

magnesium
magnesium glycinate
magnesium citrate
magnesium malate
magnesium oxide
magnesium threonate
magnesium l-threonate
magnesium taurate
magnesium bisglycinate

Best supplements for Magnesium

Top-scoring supplements in our catalog that list Magnesium on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.

Nutricost

Magnesium+ (Extra Strength) Capsules

Thorne

Magnesium Glycinate

Transparent Labs

Magnesium Bisglycinate Capsules

Thorne

MediClear-SGS™ - Vanilla

Basic Nutrients 2/Day

Thorne

Basic Prenatal

Deep dive

For mechanism of action, dosing protocols, evidence grade, and interaction warnings on Magnesium, see the full encyclopedia entry:

Electrolytes (Sodium/Potassium/Magnesium) encyclopedia entry →

Conditions where Magnesium has evidence

Magnesium appears on the supplement list for the following condition pages — each links to the full evidence summary, dose, and lifestyle context.

Research on Magnesium

Peer-reviewed studies in our research database that reference Magnesium. Each entry links to a detailed methodology review.

Guides covering Magnesium

Long-form articles in our guide library that go deeper on Magnesium — comparisons, protocols, and reviews.

Frequently asked questions

What is the daily target for Magnesium?

The fda daily value for Magnesium is 420 mg per day for adults. The Tolerable Upper Intake Level is 350 mg/day from food and supplements combined.

What foods are highest in Magnesium?

Pumpkin seeds (raw) (150 mg per 1 oz); Almonds (80 mg per 1 oz); Cooked spinach (160 mg per 1 cup). See the food sources section below for the full list.

What is the best form of Magnesium to supplement?

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.

What are the signs of Magnesium deficiency?

Muscle cramps, twitches, restless legs; Fatigue, irritability, poor sleep quality; Cardiac arrhythmias (palpitations, PVCs).

Who is most at risk for low Magnesium?

Long-term PPI users (PPIs reduce intestinal magnesium absorption); Loop diuretics, thiazides — increase urinary magnesium loss; Type 2 diabetes — magnesium is lost through glycosuria.

Related major minerals

Track your full intake

Formulate's free web app aggregates Magnesium (and ~40 other nutrients) across every supplement in your stack — flagging underdoses, overlaps, and upper-limit overshoots in one view.

Track your intake free →

Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Targets and upper limits are general adult reference values; individual needs vary by age, sex, pregnancy status, and clinical context.