Magnesium deficiency from stress: how magnesium, stress and cortisol are linked

Project finished, kids in bed, a few last emails answered – and in the evening your eyelid twitches, your calves cramp and your mind will not settle. You may have heard that stress “drains” magnesium. But is that true? And what does the stress hormone cortisol have to do with it?

Here you will learn what happens in the body during long-term stress, why stress and magnesium deficiency can reinforce each other, how a deficiency may show and how magnesium and cortisol can be measured.

Stress and magnesium: what happens in the body

Under stress, the body switches to alert mode. Via the stress axis of hypothalamus, pituitary and adrenal glands, adrenaline, noradrenaline and cortisol are released. Pulse, blood pressure and blood sugar rise, muscles tense.

Magnesium acts like a brake in this system. It dampens the excitability of nerve and muscle cells and is involved in regulating the stress axis. A review describes magnesium as playing a key inhibitory role in the normal stress response (PubMed 33260549). Overall, magnesium is involved in more than 600 enzymatic reactions, including energy metabolism (PubMed 25540137).

Magnesium deficiency from stress: the vicious circle

Experts speak of a vicious circle: stress can increase magnesium loss, for example because stress hormones shift magnesium out of cells and more is excreted via the kidneys. A low magnesium status can in turn increase sensitivity to stress (PubMed 33260549) (PubMed 7836621). This concept was formulated in the 1990s and re-examined in a more recent review in light of current data (PubMed 33260549).

What does that mean in everyday life? Put factually: long-term stress can increase magnesium requirements and losses, and people whose intake is already low may slip into deficiency more easily (PubMed 29920004).

Other factors: what else affects magnesium balance

Stress is rarely the only factor. Many people take in less magnesium than recommended, for example when they eat little whole grain, pulses, nuts and green vegetables (PubMed 30513803). Regular alcohol consumption, certain medicines such as proton pump inhibitors or some diuretics, and diseases of the gut and kidneys can also affect magnesium balance (PubMed 25540137).

If you take medicines that can affect magnesium balance, mention it to your doctor. Do not stop a prescribed medication without talking to your doctor first.

Magnesium under stress: possible signs of a deficiency

Textbooks list muscle twitching and cramps, inner restlessness, tiredness and exhaustion as typical signs of magnesium deficiency (PubMed 25540137). How stress and inner restlessness can disturb sleep is covered in Sleep problems caused by stress. These complaints are non-specific, however. They can also come from lack of sleep, other nutrients or entirely different causes.

Palpitations, a racing heart, persistent muscle cramps or numbness should therefore be checked by a doctor rather than self-classified as magnesium deficiency.

What is officially authorised for magnesium: magnesium contributes to normal functioning of the nervous system, normal psychological function, normal muscle function and the reduction of tiredness and fatigue. Whether a magnesium supplement helps against stress or anxiety, however, is not reliably proven: a systematic review found some indications in people with increased vulnerability but rated the quality of the studies as low (PubMed 28445426).

Who is particularly affected

Low magnesium status is described more often in people with a less wholesome diet, regular alcohol intake, long-term use of proton pump inhibitors or diuretics, or with type 2 diabetes, chronic bowel diseases or kidney diseases (PubMed 25540137). If a long period of stress is added, for example from caring for relatives, shift work or pressure at work, these factors can add up (PubMed 33260549). Older people also often take in less magnesium from their diet (PubMed 30513803).

Measure instead of guessing: testing magnesium and cortisol

Magnesium: Only about one percent of the body’s magnesium is in the blood; most is stored in bones, muscles and other cells. The usual serum value can therefore be within the normal range even when stores are low (PubMed 25540137) (PubMed 30513803). The whole blood mineral analysis measures magnesium in whole blood, i.e. blood fluid and blood cells together, plus zinc, selenium, copper, iron, potassium, sodium and calcium.

Cortisol: Cortisol follows a daily rhythm. It rises sharply in the first 30 to 45 minutes after waking and falls towards the evening (PubMed 26563991). A single value therefore says little. More on the daily pattern in Cortisol and melatonin: the two opposing players of your day. The cortisol day profile measures cortisol in saliva in the morning, at midday and in the evening, plus DHEA from the morning sample. Salivary cortisol is an established marker in stress research but has to be read in context (PubMed 19095358). It is crucial to take the samples exactly at the specified times (PubMed 26563991).

What to discuss with professionals

A result is the start of a conversation, not a verdict. These questions can help:

• What does my diet look like, and how much magnesium do I get from it?
• Am I taking medicines that can affect magnesium balance?
• Does my cortisol pattern fit my symptoms and my daily life?
• Are there other causes of my complaints that should be clarified?
• Is supplementation necessary at all – and if so, in what form?

The ORY expert team, your doctor or your naturopath can help you interpret your mineral and cortisol values.

In short

• Magnesium acts like a brake on nerves and muscles in the stress response (PubMed 33260549).
• Stress can increase magnesium loss, and low magnesium status can increase stress sensitivity – a possible vicious circle (PubMed 33260549).
• Diet, alcohol, medicines and diseases also affect magnesium balance (PubMed 25540137).
• The serum value does not always reflect stores; whole blood gives a different picture (PubMed 30513803).
• Cortisol is more meaningfully measured as a day profile than as a single value (PubMed 26563991).

Frequently asked questions

Does stress cause magnesium deficiency?

Stress can increase magnesium loss via the kidneys. Whether this leads to a deficiency also depends on diet, medicines and health status (PubMed 33260549) (PubMed 29920004).

Is stress a “magnesium thief”?

The term is colloquial and exaggerated. What it means factually is that long-term stress can strain magnesium balance. Science describes a vicious circle of stress and low magnesium status (PubMed 33260549).

What else affects magnesium balance besides stress?

Factors mentioned include a low-magnesium diet, regular alcohol, certain medicines such as proton pump inhibitors or diuretics, and diseases of the gut and kidneys (PubMed 25540137) (PubMed 30513803).

What does magnesium have to do with cortisol?

Magnesium is involved in regulating the stress axis, which also controls cortisol release (PubMed 33260549). Whether a magnesium supplement changes cortisol levels in healthy people is not sufficiently proven.

Can magnesium reduce stress?

Magnesium contributes to normal psychological function and normal functioning of the nervous system. That a supplement relieves stress or anxiety is not reliably proven; the studies so far are of low quality (PubMed 28445426).

Is magnesium requirement higher under stress?

Studies suggest that stress can increase magnesium loss (PubMed 33260549). There is no separate official reference value for “magnesium requirement under stress”. Whether your supply is adequate can be measured.

How can magnesium deficiency be detected?

The usual serum value only captures a small part of the body’s magnesium and can be normal despite low stores (PubMed 30513803). A whole blood analysis includes the blood cells. Results should be discussed with professionals.

Sources

1. Pickering G et al. Magnesium Status and Stress: The Vicious Circle Concept Revisited. Nutrients. 2020. PubMed 33260549
2. Seelig MS. Consequences of magnesium deficiency on the enhancement of stress reactions; preventive and therapeutic implications. J Am Coll Nutr. 1994. PubMed 7836621
3. Cuciureanu MD, Vink R. Magnesium and stress. In: Vink R, Nechifor M (eds.). Magnesium in the Central Nervous System. University of Adelaide Press. 2011. PubMed 29920004
4. de Baaij JHF et al. Magnesium in man: implications for health and disease. Physiol Rev. 2015. PubMed 25540137
5. Razzaque MS. Magnesium: Are We Consuming Enough? Nutrients. 2018. PubMed 30513803
6. Boyle NB et al. The Effects of Magnesium Supplementation on Subjective Anxiety and Stress – A Systematic Review. Nutrients. 2017. PubMed 28445426
7. Stalder T et al. Assessment of the cortisol awakening response: Expert consensus guidelines. Psychoneuroendocrinology. 2016. PubMed 26563991
8. Hellhammer DH et al. Salivary cortisol as a biomarker in stress research. Psychoneuroendocrinology. 2009. PubMed 19095358