Magnesium
mineral
ApprovedGeneral information about nutrients. No diagnosis, no medical advice. If you take medication, are pregnant or have a medical condition, talk to your doctor before taking supplements.
Overview
Mineral involved in more than 300 enzymatic reactions. Magnesium contributes to normal muscle function. Magnesium contributes to normal functioning of the nervous system.
Interactions
Vitamin B6 (as PLP) increases magnesium transport into cells by enhancing membrane transporter activity. B6 deficiency reduces intracellular Mg accumulation.
Vitamin D3 regulates magnesium absorption in the intestine and renal reabsorption. The two minerals are bidirectionally dependent — low D3 leads to Mg wasting.
Research status
Cofactor in more than 600 enzymatic reactions, including DNA repair.
Top 5 food sources
Expert opinions
NIH
The NIH UL of 350 mg/day applies only to supplemental magnesium — dietary magnesium from nuts, seeds, greens, and whole grains has no upper limit because intestinal absorption self-regulates. The cap is based on osmotic diarrhea thresholds, not systemic toxicity. RDAs are 400–420 mg/day for men and 310–320 mg/day for women; surveys show 50 % of US adults fall below the EAR. At-risk groups include alcohol users, diabetics, and chronic PPI users. Serum magnesium is insensitive — RBC magnesium is the more reliable marker.
Recommended dose: 310–420 mg (total)
Source: NIH
Bryan Johnson Blueprint
Johnson takes magnesium L-threonate (Magtein) in the evening. The Blueprint evening stack pairs threonate with glycinate. Standard dose is about 2 g Magtein (about 144 mg elemental). Serum Mg and RBC Mg are monitored alongside HRV and sleep-quality metrics.
Recommended dose: 400–500 mg
Source: Blueprint Protocol
Dr. Andrew Huberman
Huberman takes 145 mg elemental Mg from Magtein 30 to 60 min before bed as a core element of his evening stack, alongside apigenin and L-theanine. He considers glycinate a cost-effective alternative form, and many users rotate or combine forms. He avoids magnesium oxide.
Recommended dose: 145 mg (as threonate)
Source: Huberman Lab
Dr. Rhonda Patrick
Patrick highlights that serum magnesium is a poor marker because homeostasis preserves it at the expense of intracellular stores, so she recommends RBC magnesium or ionized Mg testing. She cites magnesium as a cofactor for over 300 enzymes, including those in mitochondrial ATP production. She favors glycinate or citrate at 300 to 400 mg elemental daily, adjusted by labs and GI tolerance.
Recommended dose: 300–400 mg
Source: FoundMyFitness
Current Research
Subclinical magnesium deficiency is present in about 30 to 50% of adults by RBC or ionized-Mg testing, yet routine serum labs miss it because only 1% of body magnesium is extracellular. Absorption differs markedly by form: glycinate (about 80%), threonate and taurate (high, tissue-targeted), citrate (about 30%, mildly laxative), oxide (<5%).
Source: Current Research
Dr. Strunz
Strunz regards magnesium as the most commonly deficient mineral and recommends 400 to 800 mg elemental daily split across meals, aiming for RBC magnesium in the upper quartile. Preferred forms are glycinate, threonate and malate, while oxide is dismissed as poorly absorbed and laxative. He combines magnesium with vitamin D3 and B6.
Recommended dose: 400–600 mg
Source: Dr. Strunz
Expert profiles summarise publicly available statements. The named people do not cooperate with Stackwell and have not authorised these summaries. Not medical advice.
Universal agreement on widespread deficiency. All profiles recommend supplementation.