HoldsUp

Dr. Eric Berg DC · 2026-05-05 · Eric Berg (host)

The #1 Magnesium Mistake Everyone Makes

15 research-tied claims examined: 2 contradicted 1 overstated 1 context 7 supported 4 unverified

2

Contradicted by research

0:05:08Eric Berg (host)contradictedmoderate

The glycinate component of magnesium glycinate increases GABA to help calm the nervous system and promote sleep.

"magnesium glycinate comes with the glycinate part, which actually helps calm down the nervous system. It helps increase something called GABA, which actually can help you sleep a little bit better." (said at 0:05:08)

The speaker bundles two claims regarding the glycinate (glycine) component of magnesium glycinate: that it promotes calming/sleep, and that it works by increasing GABA. 1. Glycine and sleep: Supported. Clinical trials and animal models indicate that oral glycine supplementation can improve subjective sleep quality and promote sleep, in part by lowering core body temperature via actions on NMDA receptors in the suprachiasmatic nucleus, as well as providing inhibitory neurotransmission. 2. Glycine increasing GABA: Contradicted. Glycine does not act by increasing gamma-aminobutyric acid (GABA). Instead, glycine is itself an independent primary inhibitory neurotransmitter in the central nervous system that acts directly at its own glycine receptors (GlyRs) and serves as an NMDA receptor co-agonist. GABA and glycine represent two distinct inhibitory neurotransmitter systems.

0:13:02Eric Berg (host)contradictedmoderate

Sixty percent of depression cases today are classified as treatment resistant.

"60% of depression nowadays is classified as treatment resistant. Okay? Because the drugs don't work." (said at 0:13:02)

The claim that 60% of depression cases are classified as treatment-resistant is contradicted by epidemiological evidence. Treatment-resistant depression (TRD)—typically defined as a lack of clinically meaningful response after at least two adequate trials of different antidepressants—is estimated to occur in approximately 30% (not 60%) of patients treated for major depressive disorder.

1

Overstated

0:04:48Eric Berg (host)overstatedmoderate

Magnesium glycinate has an 80 percent absorption rate.

"A much better form of magnesium would be to take magnesium glycinate. First of all, you won't have the GI problems, you won't have diarrhea. Secondly, you absorb 80%" (said at 0:04:48)

While magnesium glycinate (magnesium diglycinate) is generally well-tolerated with less laxative effect than inorganic salts like magnesium oxide, clinical and physiological data do not support an 80% absorption rate. In human stable isotope studies assessing fractional absorption, oral magnesium absorption generally ranges between 20% and 50% depending on dosage, individual magnesium status, and formulation. For example, a randomized crossover trial measuring 26Mg-labeled magnesium diglycinate absorption observed a fractional absorption rate of approximately 23.5%. Claiming an 80% absorption rate substantially overstates human magnesium bioavailability.

1

Needs context

0:10:15Eric Berg (host)needs contextlow

Elevated cortisol levels and sleep deprivation increase the depletion of magnesium in the body.

"Because as soon as you can't sleep, cortisol goes up. Cortisol then depletes more magnesium. The requirement of magnesium goes up." (said at 0:10:15)

The interaction between physiological stress, elevated cortisol, and magnesium depletion is a recognized hypothesis in nutritional biochemistry (often referred to as the 'magnesium-stress vicious circle'). Observational studies and reviews indicate that psychological or physiological stress, accompanied by activation of the hypothalamic-pituitary-adrenal (HPA) axis and higher cortisol levels, is associated with increased urinary excretion of magnesium and lower circulating magnesium concentrations. However, direct evidence establishing that acute sleep loss or elevated cortisol drives clinically significant systemic magnesium depletion requiring increased dietary intake in healthy adults remains primarily supported by cross-sectional and narrative review literature rather than robust randomized trials.

7

Supported by research

0:02:04Eric Berg (host)supportedhigh

The Recommended Dietary Allowance (RDA) for magnesium was established in 1997 based on reference body weights of 133 pounds for women and 166 pounds for men.

"Now, the RDA for magnesium was set up in 1997 based on body weight, which correlated to women that weigh 133 lb, which nowadays a lot of women weigh more than that, and men that weighed 166 lb, which nowadays they weigh a lot more." (said at 0:02:04)

The 1997 Dietary Reference Intakes (DRIs) established by the Institute of Medicine set Recommended Dietary Allowances (RDAs) for magnesium using standard reference body weights based on historical adult reference averages (approximately 133–134 lb / 61 kg for women and 166–167 lb / 76 kg for men). Published research confirms that these 1997 reference weights were lower than modern average body weights, and recalculating magnesium requirements using updated body weight data yields higher daily recommended intakes for both men and women.

0:03:40Eric Berg (host)supportedmoderate

Magnesium oxide has an absorption rate of only 4 percent in the human body.

"But, the problem with magnesium oxide is it only has a 4% absorption rate. That means if you're taking a 400 mg magnesium oxide pill, the body might absorb 16 mg." (said at 0:03:40)

Human bioavailability research supports the claim that magnesium oxide has a fractional absorption rate of approximately 4%. In a clinical comparison of commercial oral magnesium preparations in healthy volunteers, urinary magnesium excretion measurements demonstrated that magnesium oxide had a fractional absorption rate of approximately 4%, which was significantly lower than organic salts and other inorganic forms like magnesium chloride.

0:06:12Eric Berg (host)supportedhigh

Magnesium acts as a cofactor at glutamate receptors to turn down neuronal excitation.

"Glutamate is the on and then GABA is the off switch or the calming effect in the neurons. And so, what you need to know is magnesium is the helper, it's called the cofactor, for this receptor to help wind this system down. To allow the overexcited neurons to turn down. But when magnesium is low, we have no way of turning down this gas pedal." (said at 0:06:12)

Extracellular magnesium is a well-established physiological regulator of neuronal excitability. It acts primarily as a voltage-dependent channel blocker of N-methyl-D-aspartate (NMDA) subtype glutamate receptors. At resting membrane potentials, hydrated magnesium ions lodge within the receptor pore to prevent calcium influx and dampen baseline excitatory signaling, only unblocking upon sufficient membrane depolarization. When extracellular magnesium concentrations drop, this blockade is diminished, resulting in heightened NMDA receptor activation and increased neuronal excitability.

  • supports: Ageing, hippocampal synaptic activity and magnesium. (Magnesium research 2006) · cited 73x in the literature
    "One of general properties of magnesium at presynaptic fibre terminals is to reduce transmitter release. At the postsynaptic level, it closely controls the activation of the N-methyl-D-aspartate receptor, a subtype of glutamate receptor, which is critical for the expression of long-term changes in synaptic transmission." (abstract, passage verified)
    pubmed
  • supports: Molecular mechanism of calcium permeability and magnesium block in NMDA receptors. (Nature neuroscience 2026) · cited 2x in the literature
    "N-methyl-D-aspartate-type glutamate receptors, which bind glutamate and glycine and facilitate Ca 2+ influx upon relief of Mg 2+ channel block during membrane depolarization. However, the structural mechanism underlying Ca 2+ permeability and Mg 2+ blockade in N-methyl-D-aspartate-type glutamate receptors has yet to be fully elucidated. Here we demonstrate using single-particle cryo-electron microscopy that Ca 2+ permeation through the narrow constriction of the cation selectivity filter involves partial dehydration, as evidenced by several Ca 2+ binding sites. In contrast, Mg 2+ binds outside of the selectivity filter through a water network and remains hydrated, thereby acting as a channel blocker." (abstract, passage verified)
    pubmedfull study (doi)
0:10:55Eric Berg (host)supportedhigh

Only 1% of total body magnesium is located in blood plasma, while 99% resides outside the blood.

"Only 1% is in your plasma. So if you're deficient in magnesium, your bones will literally dump some of the magnesium into the blood to maintain that 1%. So you cannot accurately figure out how much magnesium you have through your blood. 99% of it is not in the blood." (said at 0:10:55)

Established physiological and biochemical evidence supports the claim. Total body magnesium is distributed predominantly in bone (approximately 50–60%) and soft tissues/intracellular compartments, with less than 1% to 2% located in blood plasma and extracellular fluid. Because plasma magnesium concentration is tightly defended by renal conservation and exchange with bone reserves, normal serum or plasma levels can persist despite significant tissue or intracellular depletion, limiting the diagnostic value of blood testing alone for total body magnesium status.

0:11:45Eric Berg (host)supportedhigh

Red blood cells contain no mitochondria.

"Well, guess what? There is no mitochondria in the red blood cell. So it's not a good test to evaluate how much magnesium you have." (said at 0:11:45)

Mature mammalian erythrocytes (red blood cells) do not contain mitochondria. During the terminal stages of erythropoiesis, erythroblasts enucleate and clear all intracellular organelles, including mitochondria, via programmed autophagy (mitophagy). As a result, mature red blood cells rely entirely on anaerobic glycolysis for ATP generation.

0:12:03Eric Berg (host)supportedlow

In one tissue biopsy study, 50% of people who were magnesium deficient showed normal blood magnesium levels.

"In one study, they found 50% of people that were deficient had normal blood magnesium levels. And this was a test that they actually did a biopsy and they tested the tissues directly because that's another way to figure out if you have enough magnesium, do a biopsy." (said at 0:12:03)

The statement accurately reflects published findings from a muscle biopsy study in clinical patients. In a 1988 study of 32 patients admitted to a pulmonary intensive care unit who underwent quadriceps femoris needle biopsies, 15 patients (47%, or approximately 50%) were found to have tissue magnesium deficiency despite having normal serum magnesium levels. Overall, serum magnesium accounts for less than 1% of total body magnesium stores and is recognized as a poor indicator of intracellular magnesium status. However, the evidence comes from a small, specific clinical cohort (ICU patients with respiratory failure), yielding low certainty for generalizability across healthy populations.

0:13:23Eric Berg (host)supportedmoderate

Modern NPK (nitrogen, phosphorus, potassium) fertilizers inhibit magnesium absorption in agricultural crops.

"And also, the problem is it's very difficult to get magnesium from our foods because the modern farming fertilizers with the NPK, nitrogen, phosphorus, and potassium, tend to inhibit magnesium." (said at 0:13:23)

Plant physiology and agricultural research confirm that high potassium (K+) concentrations, such as those supplied by conventional NPK (nitrogen, phosphorus, potassium) fertilization, competitively inhibit magnesium (Mg2+) uptake by crop roots. Potassium and magnesium share non-specific cation uptake pathways, and high K+/Mg2+ ratios in soil or hydroponic media are a well-documented primary driver of induced magnesium deficiency in crops.

4

No source found (not proven false)

0:02:38Eric Berg (host)unverifiedvery low

Studies demonstrating improvements in anxiety, depression, blood pressure, and migraines use magnesium doses of up to 800 mg per day or higher.

"We're not talking about the doses they even used in certain studies that showed improvements in anxiety, depression, blood pressure, and migraines. Those studies use up to like 800 mg of magnesium per day, sometimes for weeks and sometimes even higher than that." (said at 0:02:38)

No published record matching the claim that clinical studies demonstrating improvements in anxiety, depression, blood pressure, and migraines use magnesium doses of up to 800 mg per day or higher was located; this does not prove the claim false.

0:11:31Eric Berg (host)unverifiedvery low

65 percent of intracellular magnesium is bound to ATP in mitochondria.

"65% of the magnesium is attached to what's called ATP in your mitochondria. Because we desperately need magnesium to run our energy factory." (said at 0:11:31)

No published record matching the claim that 65% of intracellular magnesium is bound to ATP in mitochondria was located; this does not prove the claim false. In cellular biology, magnesium binds strongly to ATP (forming Mg-ATP complexes essential for enzymatic reactions and energy production), and mitochondria serve as major intracellular magnesium stores. However, published literature typically identifies bone as containing roughly 60% to 65% of total body magnesium, while intracellularly, the majority of ATP is complexed with magnesium throughout the cell, with no evidence confirming the specific 65% mitochondrial ATP-bound figure.

0:12:27Eric Berg (host)unverifiedvery low

A study by Dr. P.G. Weston published in the American Journal of Psychiatry showed that giving 500 to 1,200 mg/day of magnesium improved 220 out of 250 patients with depression.

"A doctor named P.G. Weston gave magnesium to 50 patients with severe agitated depression. Well, guess what he found? 220 out of 250 depressed people improved. That is a 90% success rate. That study was published in the first volume of the American Journal of Psychiatry. And of course, it's been forgotten, but it's been sitting there for over 100 years. And in that study, they didn't give the 400 mg per day. They gave between 500 and 1,200 mg per day." (said at 0:12:27)

No published record matching the specific 100-year-old study by Dr. P.G. Weston describing 220 of 250 patients with depression improving on 500 to 1,200 mg/day of magnesium was located; this does not prove the claim false.

0:04:11Eric Berg (host)unverifiedvery low

Unabsorbed oral magnesium causes gastrointestinal distress and diarrhea by drawing water into the intestinal lumen.

"all of that unabsorbed magnesium pulls water out of your intestines." (said at 0:04:11)

No published record matching the claim that unabsorbed oral magnesium draws water into the intestinal lumen to cause diarrhea was located; this does not prove the claim false.

Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.