The Daily Foundation
Magnesium
Magnesium
Citrate
The mineral that supports over 300 enzymatic processes. Dosed at 114mg elemental. Every serving.
114mg elemental per serving · 19mg per capsule · 6 capsules daily
0
Elemental Magnesium Per Serving
0
Enzymatic Reactions Supported
0
Of Adults Estimated Deficient
0
Form. Citrate. Chosen for Absorption.
What It Does
Three things. All proven.
Muscle Function & Recovery
Magnesium is required for muscle contraction, relaxation and protein synthesis. Low magnesium directly impairs neuromuscular function and slows recovery from training. It is the foundational mineral for anyone who moves under load.
Energy Metabolism
Magnesium is a required cofactor for ATP synthesis. Without adequate magnesium, your mitochondria cannot produce energy efficiently. Every cell in your body that generates energy does so with magnesium as a structural component of the process.
Sleep Quality & Nervous System
Magnesium modulates NMDA receptors and supports GABA activity, the primary inhibitory neurotransmitter system responsible for calming neural activity. Adequate magnesium supports healthy sleep architecture and reduces nervous system hyperexcitability.
The Science
The mineral that does everything quietly.
Magnesium may be the most important mineral you are not paying enough attention to. It is the fourth most abundant mineral in the human body and the second most abundant intracellular cation after potassium. It acts as a cofactor in over 300 enzymatic reactions, participates directly in DNA synthesis and repair, and is a structural component of every molecule of ATP produced in your cells.
The reason magnesium deficiency is so common despite being a widely available mineral in food is threefold. Modern agricultural soil depletion has reduced magnesium content in crops by up to 30% over recent decades. Processed food diets replace magnesium-dense whole foods with low-magnesium alternatives. And high training loads, stress and caffeine consumption all accelerate urinary magnesium excretion, increasing demand precisely when intake is already insufficient.
Subclinical magnesium deficiency, meaning insufficient stores that do not meet the diagnostic threshold for clinical deficiency but still impair function, is estimated to affect between 50 and 80% of Western adults. This is not a niche problem. It is a broad, systemic one with real consequences for energy, sleep, recovery and cardiovascular health.
Why most people are running low and do not know it.
Standard blood tests measure serum magnesium, the magnesium circulating in your blood plasma. This represents less than 1% of total body magnesium. The other 99% is stored in bone, muscle and soft tissue. Your body will deplete these stores to maintain serum levels within normal range, meaning a normal blood test result does not rule out functional deficiency at the tissue level.
This creates a situation where magnesium deficiency is significantly underdiagnosed. Symptoms, fatigue, muscle cramps, poor sleep, anxiety, impaired recovery and reduced exercise tolerance, are widespread and frequently attributed to other causes. The connection to low magnesium status is rarely made because the standard diagnostic test is not sensitive enough to detect it.
Magnesium deficiency also has a self-reinforcing quality. Low magnesium impairs the sodium-potassium pump, which further disrupts mineral balance and makes correction through diet alone increasingly difficult. The most reliable way to correct functional deficiency is consistent supplementation with a well-absorbed form.
A normal serum magnesium result does not mean your tissues are adequately supplied. The blood test tells you almost nothing about your functional magnesium status.
Can you not just eat more spinach?
Magnesium is theoretically abundant in food. Dark leafy greens, nuts, seeds, legumes and whole grains all contain meaningful amounts. The adult reference nutrient intake in the UK is 300mg for women and 400mg for men. In principle this is achievable through diet. In practice, the majority of people fall consistently short.
The practical barriers are multiple. Magnesium in plant foods is bound to phytates and oxalates that reduce bioavailability. The magnesium content of vegetables has declined significantly due to soil depletion. High protein diets increase urinary magnesium loss. Alcohol, caffeine and diuretic medications all increase excretion. And for anyone training seriously, requirements are elevated beyond the standard reference values.
The question is not whether you could theoretically meet magnesium requirements through diet. The question is whether you consistently do. For the majority of people who train, the honest answer is no. The 114mg elemental dose in The Daily Foundation is not designed to replace dietary magnesium. It is designed to close the gap that diet leaves open.
The gap between theoretical dietary intake and actual magnesium status in people who train is real, measurable and worth closing.
Why magnesium citrate and what you should know about it.
Not all magnesium is equal in terms of bioavailability. Magnesium oxide, the most common and cheapest form used in supplements, has an absorption rate of approximately 4%. A 200mg dose of magnesium oxide delivers roughly 8mg of usable elemental magnesium. It is used because it is cheap, not because it works.
Magnesium citrate is magnesium bound to citric acid. It is water soluble, which means it dissolves readily in the gastrointestinal tract and is available for absorption. Research consistently places magnesium citrate among the most bioavailable oral forms, with absorption rates between 25 and 35% depending on individual factors and baseline status.
Magnesium glycinate and magnesium threonate are also well-absorbed forms, each with specific use cases. Magnesium citrate is the form with the broadest research base across general magnesium status correction, which is why it was selected for this formula over the alternative chelated forms that are often more expensive with narrower evidence for general use.
The form determines whether the dose actually reaches your cells. Magnesium oxide at any dose is largely a waste. Citrate is not.
Who benefits most from magnesium supplementation?
01
Anyone who trains regularly. Exercise increases urinary magnesium excretion and elevates requirements for muscle contraction, protein synthesis and energy production. The harder and more frequently you train the greater your magnesium demand above baseline.
02
People with poor sleep quality. Magnesium plays a direct role in regulating the nervous system activity that enables sleep onset and sleep quality. Deficiency is associated with lighter, more fragmented sleep. Correction produces measurable improvements in multiple sleep parameters.
03
High coffee and alcohol consumers. Both caffeine and alcohol increase urinary magnesium excretion significantly. If your lifestyle involves regular consumption of either, your baseline magnesium loss is higher than the general population reference values account for.
04
Anyone under chronic stress. Stress hormones, particularly cortisol, mobilise magnesium out of cells and accelerate its excretion. Chronic stress and chronic low magnesium are mutually reinforcing. Addressing magnesium status is part of addressing the physiological consequences of stress.
05
Anyone over forty managing cardiovascular health. Magnesium has documented roles in blood pressure regulation, arterial elasticity and cardiac rhythm. The epidemiological evidence linking adequate magnesium status to reduced cardiovascular risk is substantial and consistent.
Beyond the gym. What else magnesium supports.
The performance narrative around magnesium is accurate but incomplete. Magnesium is involved in insulin signalling and glucose metabolism, making it relevant for anyone managing body composition and metabolic health. Adequate magnesium status is associated with improved insulin sensitivity. Deficiency is independently associated with increased type 2 diabetes risk.
Magnesium also plays a structural role in bone mineralisation that is frequently overlooked in favour of calcium. Approximately 60% of total body magnesium is stored in bone. Magnesium is required for the proper deposition and crystal formation of calcium phosphate in bone matrix. You cannot optimise bone density with calcium and vitamin D3 while ignoring magnesium.
The interaction between magnesium and vitamin D3, which is also present in The Daily Foundation, is clinically relevant. Magnesium is required for the enzymatic conversion of vitamin D3 into its active form. Supplementing vitamin D3 without adequate magnesium may partially limit the conversion to the active metabolite that drives the documented benefits of vitamin D3 supplementation.
Magnesium is required to activate the vitamin D3 in this formula. The two work together. Neither operates in isolation.
Safe, well tolerated and hard to overdo from supplements.
Magnesium from food carries no upper tolerable intake level because excess dietary magnesium is excreted efficiently by healthy kidneys. Supplemental magnesium has a defined upper tolerable intake of 400mg elemental per day from supplements alone, established to account for the laxative effect that excess supplemental magnesium can produce at high doses.
The 114mg elemental dose in The Daily Foundation sits well below this threshold. Even combined with a magnesium-rich diet, reaching the upper tolerable level from supplementation at this dose is essentially impossible in practice. The most common side effect of magnesium supplementation, loose stools, is a dose-dependent phenomenon that occurs reliably at high single doses and rarely at the sustained moderate doses used in daily supplementation like this formula.
There are no known long-term safety concerns with magnesium citrate at standard supplementation doses in healthy adults. The compound is widely studied and has been used in clinical and consumer settings for decades without a meaningful adverse event profile emerging at these doses.
If you have kidney disease or take medications that affect potassium balance, speak to your doctor before supplementing magnesium. For everyone else, the safety record at this dose is as clean as any mineral in this space.
114mg elemental daily. Well within established safety parameters. The form absorbs. The dose is meaningful. Both matter.
At a glance
Form
Magnesium Citrate
Dose Per Capsule
19mg elemental
Daily Serving
114mg elemental (6 capsules)
NRV
30% (based on 375mg NRV)
Best Taken
With food. Evening timing may support sleep quality.
Works With
Vitamin D3, Zinc and all other ingredients in The Daily Foundation
What the Research Shows
Performance
Athletes have measurably higher magnesium requirements than sedentary people.
A review of human intervention studies in Nutrients (2017) found that magnesium supplementation improved muscle function, reduced oxygen consumption during exercise and decreased blood lactate accumulation during physical effort. Benefits were most pronounced in individuals with lower baseline magnesium status, the group most active people fall into.
Sleep
Eight weeks of supplementation measurably improves sleep quality.
A double-blind placebo-controlled trial published in the Journal of Research in Medical Sciences found significant improvements in sleep onset time, duration, efficiency and early waking in the magnesium group. Serum magnesium and melatonin rose. Cortisol fell. The mechanism is GABA receptor regulation.
Blood Glucose
Insulin resistance improves with magnesium repletion in deficient individuals.
A meta-analysis of randomised controlled trials in the European Journal of Clinical Nutrition found that magnesium supplementation significantly reduced fasting blood glucose and improved insulin resistance markers. Effects were stronger in those with lower baseline magnesium, reinforcing that deficiency correction drives the benefit.
Anxiety
Consistent reductions in subjective anxiety scores across multiple human trials.
A systematic review in Nutrients (2017) found modest but consistent reductions in anxiety scores following magnesium supplementation, particularly in individuals with mild to moderate anxiety and low baseline magnesium status. The mechanism is consistent with magnesium's role in GABA receptor modulation and HPA axis regulation.
Clinical context
Standard blood tests miss magnesium deficiency. By design.
Only 1% of your body's magnesium circulates in blood. Serum levels are tightly regulated and remain stable even when cellular and tissue magnesium is depleted. By the time a routine blood panel flags low magnesium, deficiency is often well established at the tissue level. The consequence is that most people who are suboptimally magnesiated have no idea. The symptoms, slower recovery, poor sleep, muscle tightness, elevated anxiety, are attributed to overtraining or life stress rather than a mineral sitting one or two food servings short of adequacy every single day.
300 enzymatic reactions. Every one of them needs this.
