Magnesium: widely under-eaten, and widely over-promised

Around half the population takes in less magnesium than the official requirement says they need, and that requirement is itself argued about by the people who measured it. What nobody argues about is the distance between what a magnesium bottle promises and what the trials found.

What it does in the body

• Magnesium is a cofactor in more than 300 enzyme systems, including those regulating protein synthesis, muscle and nerve function, blood glucose and blood pressure. Evidence E source

How much you need

• The RDA for magnesium is 400–420 mg a day for adult men and 310–320 mg for adult women, depending on age. — adults Evidence E source
• The upper limit for magnesium applies only to supplements and medicines, not to magnesium in food and drink. Evidence E source
• Pooling every tightly controlled magnesium balance study run at the US Department of Agriculture's Grand Forks centre, the body stops losing magnesium at an intake of about 165 mg a day, well under half the current recommendation. — healthy adults: 150 women averaging 51 years and 93 men averaging 28 years, on controlled diets of at least 28 days with magnesium intakes between 84 and 598 mg a day Evidence A source
• Reading the same balance evidence, researchers who ran the metabolic wards put the average requirement at about 175 mg a day and the recommended intake at about 250 mg for a 70 kg adult, below the official US and Canadian figures. — healthy adults of about 70 kg; requirements scaled up or down with body weight Evidence C source
• Feeding postmenopausal women a Western diet supplying only 107 mg of magnesium a day tipped them into negative balance and changed how their bodies handled calcium. — postmenopausal women aged 49 to 71 living in a metabolic research unit on a basal Western-type diet, with or without 220 mg a day of supplemental magnesium gluconate Evidence B source
• For heart disease the protective association with dietary magnesium flattens out above roughly 250 milligrams a day, well below the recommended intake. — adults in 16 prospective cohorts Evidence C source
• The magnesium in a vegetable is a property of the field it grew in, not of the vegetable: across 140 studies of pepper, content tracked soil, rainfall and mean temperature. — pepper (Capsicum spp.) fruit sampled worldwide; 649 to 811 datapoints per mineral Evidence C source
• Food composition tables are a moving target in one direction: over the last decade the mineral quality of pepper fell, most of all for iron and zinc. — pepper fruit sampled worldwide over roughly a decade Evidence C source
• The 420 mg on a label is not what an average person needs: it is built to cover 97 to 98 out of every 100 people, so most readers are comparing themselves against a deliberately generous target. — United States labelling for people 4 years and older Evidence E source
• Falling short of the Daily Value is not the same as being deficient, because the Daily Value was never set at the level where shortfall begins. — United States labelling Evidence E source

How well your body absorbs it

• Baking the same magnesium into wholemeal rather than white bread more than halves how much of it you absorb: 32.5% fell to 13.0% when phytic acid was added at wholemeal levels. — 8-9 healthy adults per study, each person their own control on days 1 and 3 Evidence B source
• The phytate effect is real at the amounts actually present in everyday bread, not only at laboratory doses. — healthy adults Evidence B source
• Spreading the same magnesium across the day beats drinking it in two goes: seven small servings of mineral water were absorbed at 50.7% against 32.4% for two large ones. — 12 healthy men drinking 1.5 litres of magnesium-rich natural mineral water, 126 mg of magnesium in both arms Evidence B source
• Even within one magnesium salt the packaging changes the dose you get: dissolved effervescent magnesium oxide raised urinary magnesium by 40%, the same amount in a capsule by 20%. — 13 healthy male volunteers aged 22-31 Evidence B source
• Prebiotic fiber raised magnesium absorption in postmenopausal women, but only in two thirds of them, and the responders were the ones with weaker bones. — 15 postmenopausal women, mean age 72.2 years (SD 6.4) Evidence B source

What too little does

• Early signs of magnesium deficiency are loss of appetite, nausea, vomiting, fatigue and weakness. — people with deficiency Evidence E source
• A normal blood magnesium result does not rule out a shortfall: people sitting inside the normal range still responded to supplements in metabolic ward experiments. — healthy adults studied under fully controlled intake in metabolic units Evidence C source
• Neither serum magnesium nor ionised magnesium in whole blood tracked how much magnesium people were actually eating. — adults in a pilot supplement bioavailability trial; intake measured by three-day food records with the Nutrition Data System for Research Evidence B source

Who is most likely to fall short

• 48% of Americans take in less magnesium from food and drink than the estimated average requirement. — US population, NHANES 2013–2016 Evidence C source
• Taking a proton pump inhibitor raises the odds of low blood magnesium by about 70 per cent, and doubling the dose roughly doubles it again. — adults prescribed proton pump inhibitors, compared with non-users Evidence C source
• About a third of people with type 2 diabetes have low blood magnesium, which makes diabetes one of the few settings where a deficiency is common enough to look for. — people aged 19 and over with type 2 diabetes, mean age 55.4 years and mean HbA1c 8.01 Evidence C source
• Patients who arrive in intensive care with low magnesium die about 76 per cent more often than those who do not, and need a ventilator more often too. — critically ill patients admitted to intensive care Evidence C source

What the evidence does and does not show

• Magnesium supplements lower blood pressure only marginally. — adults Evidence A source
• The American Diabetes Association says there is insufficient evidence to support routine magnesium supplements for blood sugar control in diabetes. — people with diabetes Evidence E source
• Three of four small short-term placebo-controlled trials found modest reductions in migraine frequency with up to 600 mg a day of magnesium. — people with migraine Evidence B source
• A Cochrane review of trials in older adults with night cramps found magnesium made no difference to how often the cramps came. — older adults with idiopathic night cramps, mean age 61.6 to 69.3 years, 5 trials Evidence A source
• Across seven randomised trials in 325 adults with a depressive disorder, magnesium supplements lowered depression scores. — adults with a diagnosed depressive disorder, average ages 20 to 60, 7 trials Evidence A source
• The same authors say plainly that the trials are too small to turn that result into clinical advice. — adults with a depressive disorder, 7 trials Evidence A source
• Leg cramps in pregnancy are the symptom most often blamed on magnesium, and in four randomised trials magnesium did nothing for them. — pregnant women with leg cramps, a complaint affecting 30 to 50 per cent of pregnancies twice a week or more Evidence A source
• Across the cramp trials, oral magnesium caused about half as many again minor side effects as placebo, almost all of them in the gut, while serious events were no more common. — people taking oral magnesium for skeletal muscle cramps: pregnant women, older adults and people with idiopathic cramps Evidence A source
• Magnesium oxide at 1.5 g a day works as a laxative about as well as senna, and over four weeks it caused no severe side effects at all. — patients with chronic idiopathic constipation, mean age 42 years, 93 per cent women, mean symptom duration 9.9 years Evidence B source
• Where your water is hard, some of your magnesium comes out of the tap: across ten studies, higher magnesium in drinking water went with about 11% lower coronary heart disease death. — adults in nine articles yielding ten studies; three cohort and seven retrospective designs, nine of ten from Europe Evidence C source
• Almost everything we know about magnesium in drinking water comes from a handful of northern European countries, which is why the finding should not be read as a global one. — the ten studies pooled on drinking-water magnesium and coronary heart disease death Evidence C source
• A year of drinking calcium- and magnesium-rich mineral water cut falls at six months in adults over 50, and the advantage had gone by twelve. — 98 adults aged 50 and over, 86.7% women, mean age about 63, with and without osteosarcopenia Evidence B source

What too much does

• High doses of magnesium supplements often cause diarrhoea with nausea and abdominal cramping. — people taking high-dose supplements Evidence E source
• The risk of magnesium toxicity rises when kidney function is impaired, because the body can no longer clear the excess. — people with renal impairment Evidence E source
• In people with weak kidneys, a year of high-dose magnesium produced nearly four times as many gut problems as placebo, and more deaths and heart events, with no benefit to show for it. — patients with chronic kidney disease and an estimated filtration rate of 15 to 45 ml/min, given magnesium hydroxide 15 mmol twice daily Evidence B source
• A blood magnesium above the normal range marks a worse outlook in heart failure than a level below it: the high group had the highest event rate of all three. — outpatients with heart failure and an ejection fraction of 35 per cent or less, enrolled in the GALACTIC-HF trial Evidence C source
• At 450 mg a day for half a year, in people with healthy kidneys, magnesium barely moved blood levels and caused no serious trouble. — overweight and slightly obese adults, mean age 63.2 years, 63.4 per cent women Evidence B source
• The 350 mg ceiling on magnesium supplements has no safety margin built into it at all: it is a threshold of 360 mg divided by an uncertainty factor of one. — adolescents and adults; the ceiling applies to supplements and medicines, not to food Evidence E source
• The side effect the ceiling is built on was almost never measured properly: most of the studies behind it never said what they counted as diarrhoea. — the trials cited for the 1997 upper limit and later supplementation trials Evidence E source
• The magnesium salts that upset stomachs least are not the ones most sold: gluconate and chloride are preferred for oral replacement precisely because they cause diarrhoea less often. — adults taking oral magnesium supplements Evidence E source
• Two habits make a magnesium supplement easier to tolerate, and neither is on the label: split the dose, and take it with food. — adults taking high oral magnesium doses Evidence E source

Medicines it interacts with

• Magnesium-rich supplements and medicines reduce absorption of oral bisphosphonates taken for osteoporosis. — people taking alendronate or another oral bisphosphonate Evidence E source
• Magnesium binds tetracycline and quinolone antibiotics into insoluble complexes, which is why they should not be swallowed together. — people taking doxycycline, ciprofloxacin or similar antibiotics Evidence E source
• Long-term treatment with loop or thiazide diuretics increases magnesium loss in urine and can deplete it. — people on furosemide, bumetanide, hydrochlorothiazide or ethacrynic acid Evidence E source
• Proton pump inhibitors taken for more than about a year can drive blood magnesium below normal. — people on prescription proton pump inhibitors for prolonged periods Evidence E source

What to do with this

This is a habit rather than a decision. Around half the population takes in less than they need, and the foods that fix it are ones most people already like.

A handful of nuts or seeds most days does most of the work. Wholemeal instead of white, wherever the swap does not bother you, does the rest. Legumes and dark leaves fill in. There is no counting involved and no upper limit to respect, because magnesium in food is not capped.

Supplements are a different question and a smaller one. They are sold for blood pressure, blood sugar, sleep and migraine, and the trials behind those claims are thinner than the packaging implies. If you take one anyway, expect the bathroom to tell you when the dose is too high, and treat impaired kidney function as a reason to ask a doctor first.

If you are about to ask for a blood test to settle this, know what it can and cannot do. In one group of adults, neither serum magnesium nor the ionised magnesium in whole blood tracked how much magnesium they were eating. In metabolic ward experiments, people sitting well inside the normal range still responded to supplements. A normal result does not rule a shortfall out, and there is no better test to ask for instead.

Two groups are worth checking anyway, because the odds there are high enough to justify it. About 32 per cent of people with type 2 diabetes have low blood magnesium, and people on a proton pump inhibitor run at 19.4 per cent against 13.5 per cent of everyone else, with a high dose roughly doubling the odds again.

And if you came here because of cramps in pregnancy, four randomised trials pooled together found magnesium changed neither how often the cramps came nor how well women recovered from them.

If you are choosing between bottles, the honest answer is that nobody has run the comparison you want. What exists is a narrative summary: gluconate and chloride are preferred for oral replacement because they cause diarrhoea less often, carbonate is too insoluble to absorb properly, and citrate dissolves readily enough to move the bowels more than oxide does. Even inside one salt the packaging changes what you get. Thirteen men took the same 450 mg of magnesium oxide as an effervescent tablet and as a capsule, and urinary magnesium rose 40 per cent after the tablet against 20 after the capsule.

Two habits do more than the choice of salt, and neither is on the label. Split the dose across the day and take it with food. In the cleanest measurement of the first, twelve men drinking the same 126 mg in mineral water absorbed 50.7 per cent of it in seven small servings and 32.4 per cent in two large ones.

One thing food tables cannot tell you. The magnesium in a vegetable is partly a property of the field it grew in. Across 140 studies of peppers, content tracked soil, rainfall and mean temperature, came out lowest in the poorest regions, and drifted down over the past decade. That is one crop and a pool of very different laboratories, so take it as the reason a table value is an average of somebody else's harvest.

Where to get it from food

The bottom line

The case for eating more magnesium-rich food is solid, and it means nuts, seeds, legumes and whole grains. The case for magnesium as a treatment is much weaker than the pharmacy shelf suggests. Blood pressure effects are small, diabetes effects are not established, and the migraine evidence rests on a handful of small trials. One more thing worth knowing: the safe upper limit applies only to supplements, because magnesium in food is not capped. Two findings have landed since this page was written and both are worth your attention. The requirement is contested. Pooling the controlled balance studies run at one US Department of Agriculture laboratory, the body stopped losing magnesium at 165 mg a day. The researchers who ran those wards put the recommended intake at about 250 mg for a 70 kg adult, against the official 400 to 420. And the safety line now has a trial under it. In people with chronic kidney disease, a year of magnesium hydroxide caused gut trouble in 35 of them against nine on placebo, with five deaths and six cardiovascular events against two deaths and none, and no benefit to the calcification it was meant to slow. One trial published since belongs here precisely because it does not resolve into a headline. Ninety-eight adults over 50 drank a litre a day of calcium- and magnesium-rich mineral water for a year, with falls as the main thing being counted. At six months falls were 82 per cent less frequent in the water group. At twelve months there was no difference between the groups at all. Muscle mass was higher at the end and the physical performance scores did not move. Ninety-eight people give very wide intervals, and the water carried calcium as well, so nothing in it isolates magnesium. We are reporting both halves because the trial reported both halves.

Sources

1. mg-01 · Position of an expert body · expert body statement
   Magnesium is a cofactor in more than 300 enzyme systems that regulate diverse biochemical reactions in the body, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation.
   NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
2. mg-02 · Position of an expert body · expert body recommendation
   19–30 years: 400 mg [male], 310 mg [female]; 31–50 years: 420 mg [male], 320 mg [female] (value from the source's table, not a sentence)
   NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
3. mg-03 · Position of an expert body · expert body statement
   The RDAs include magnesium from all sources—food, beverages, dietary supplements, and medications. The ULs only include magnesium from dietary supplements and medications.
   NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
4. mg-r2-1 · Meta-analysis or systematic review · pooled re-analysis and meta-analysis of controlled balance studies
   The models predicted neutral magnesium balance [defined as magnesium output (Y) equal to magnesium intake (M)] at magnesium intakes of 165 mg/d [95% prediction interval (PI): 113, 237 mg/d; Y = 19.8 + 0.880 M]...Neither age nor sex affected the relation between magnesium intake and output.
   Hunt & Johnson, American Journal of Clinical Nutrition, 2006 · checked 2026-09-17 · independently re-checked
5. mg-r2-2 · Observational data · synthesis of controlled metabolic ward studies
   Balance data obtained since 1997 indicate that the EAR and RDA for 70-kg healthy individuals are about 175 and 250 mg/day, respectively, and these DRIs decrease or increase based on body weight.
   Nielsen & Johnson, Biological Trace Element Research, 2017 · checked 2026-09-17 · independently re-checked
6. mg-r2-5 · Randomised controlled trial(s) · randomised double-blind crossover metabolic ward study
   Magnesium deprivation resulted in a non-positive magnesium balance (-0.21 mmol or -5 mg/d) that was highly positive during magnesium supplementation (+2.22 mmol or +54 mg/d)...The changes indicate that an intake of 4.40 mmol (107 mg) magnesium/d is inadequate for postmenopausal women because of changes in cellular ionic balance that may lead to pathophysiological conditions.
   Nielsen et al., Magnesium Research, 2007 · checked 2026-09-17 · independently re-checked
7. mg-r5-5 · Observational data · dose-response meta-analysis of prospective studies
   Circulating magnesium (per 0.2 mmol/L increment) was associated with a 30% lower risk of CVD (RR: 0.70; 95% CI: 0.56, 0.88 per 0.2 mmol/L) and trends toward lower risks of IHD (RR: 0.83; 95% CI: 0.75, 1.05) and fatal IHD (RR: 0.61; 95% CI: 0.37, 1.00). Dietary magnesium (per 200-mg/d increment) was not significantly associated with CVD (RR: 0.89; 95% CI: 0.75, 1.05) but was associated with a 22% lower risk of IHD (RR: 0.78; 95% CI: 0.67, 0.92).
   Del Gobbo et al., American Journal of Clinical Nutrition, 2013 · checked 2026-09-17 · independently re-checked
8. mg-e1-01 · Observational data · meta-analysis of food composition data
   Nutritional quality was optimal at mean annual temperature of 10 ℃ - 20 ℃, and was adversely affected when mean annual precipitation was < 500 mm.
   Food Research International, 2024 · checked 2026-09-18 · independently re-checked
9. mg-e1-02 · Observational data · meta-analysis of food composition data
   There had been a downward trend in pepper fruit nutritional quality over the last decade, especially for Fe and Zn.
   Food Research International, 2024 · checked 2026-09-18 · independently re-checked
10. mg-e1-11 · Position of an expert body · federal rulemaking
    While the RDA may not be the best estimate of any given individual's nutrient requirement, which is usually unknown, the RDA was developed as a target intake level for individuals and is designed to meet the nutrient needs of practically all (97 to 98 percent) individuals within a life stage and gender group.
    FDA, Food Labeling: Revision of the Nutrition and Supplement Facts Labels (proposed rule), 79 FR 11879 · checked 2026-09-18 · independently re-checked
11. mg-e1-12 · Position of an expert body · federal rulemaking
    Therefore, we tentatively conclude that RDAs, when available, provide the most appropriate basis for establishing RDIs.
    FDA, Food Labeling: Revision of the Nutrition and Supplement Facts Labels (proposed rule), 79 FR 11879 · checked 2026-09-18 · independently re-checked
12. mg-e1-05 · Randomised controlled trial(s) · randomised crossover stable-isotope trial
    The addition of phytic acid lowered fractional apparent magnesium absorption from 32.5 +/- 6.9% (no added phytic acid) to 13.0 +/- 6.9% (1.49 mmol added phytic acid; P < 0.0005) and from 32.2 +/- 12.0% (no added phytic acid) to 24.0 +/- 12.9% (0.75 mmol added phytic acid; P < 0.01).
    Bohn et al., American Journal of Clinical Nutrition, 2004 · checked 2026-09-18 · independently re-checked
13. mg-e1-06 · Randomised controlled trial(s) · randomised crossover stable-isotope trial
    The results show that fractional magnesium absorption from white-wheat bread is significantly impaired by the addition of phytic acid, in a dose-dependent manner, at amounts similar to those naturally present in whole-meal and brown bread.
    Bohn et al., American Journal of Clinical Nutrition, 2004 · checked 2026-09-18 · independently re-checked
14. mg-e1-07 · Randomised controlled trial(s) · crossover stable-isotope trial
    Higher Mg absorption (50·7 (SD 12·7) v. 32·4 (SD 8·1) %; P = 0·0007) and retention (47·5 (SD 12·9) v. 29·0 (SD 7·5) %; P = 0·0008) from Mg-rich mineral water were observed when it was consumed in seven servings compared with larger servings.
    Br J Nutr, 2011 · checked 2026-09-18 · independently re-checked
15. mg-e1-08 · Randomised controlled trial(s) · crossover clinical trial
    With standardized conditions, urinary magnesium excretion increased by 40% after ingestion of the effervescent tablets, and by only 20% after intake of the capsules.
    Urological Research, 2011 · checked 2026-09-18 · independently re-checked
16. mg-e1-09 · Randomised controlled trial(s) · randomised double-blind crossover trial
    Closer examination revealed a variation in response, with two-thirds of the subjects showing increased absorption with SYN1.
    Holloway et al., British Journal of Nutrition, 2007 · checked 2026-09-18 · independently re-checked
17. mg-05 · Position of an expert body · expert body statement
    Loss of appetite, nausea, vomiting, fatigue, and weakness are some of the early signs and symptoms of magnesium deficiency.
    NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
18. mg-r2-3 · Observational data · synthesis of controlled metabolic ward studies
    Thus, metabolic unit findings suggest that individuals with serum Mg concentrations >0.75 mmol/L (1.82 mg/L), or as high as 0.85 mmol/L (2.06 mg/dL), could have a deficit in Mg such that they respond to Mg supplementation, especially if they have a dietary intake history showing <250 mg (10.28 mmol)/day and a urinary excretion of <80 mg (3.29 mmol)/day.
    Nielsen & Johnson, Biological Trace Element Research, 2017 · checked 2026-09-17 · independently re-checked
19. mg-r2-4 · Randomised controlled trial(s) · randomised crossover study, secondary analysis
    Values for dietary magnesium, iMg2+ and s-Mg were 303.8 ± 118.9 mg/day, 1.3 ± 0.1 mg/dL and 2.2 ± 4.1 mg/dL, respectively. No association was found between dietary magnesium intake and iMg2+ -125 ± 176.95 (p = .49) or s-Mg -9.33 ± 5.04 (p = .08).
    Ansu Baidoo et al., Annals of Medicine, 2023 · checked 2026-09-17 · independently re-checked
20. mg-04 · Observational data · national survey analysis
    An analysis of data from the National Health and Nutrition Examination Survey (NHANES) of 2013–2016 found that 48% of Americans of all ages ingest less magnesium from food and beverages than their respective EARs.
    NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
21. mg-r5-1 · Observational data · meta-analysis of observational studies
    Among PPI users, 19.4% (95% CI 13.8%, 26.5%) had hypomagnesemia compared to 13.5% (95% CI 7.9%, 22.2%) among nonusers. By meta-analysis, PPI use was significantly associated with hypomagnesemia, with a pooled unadjusted OR of 1.83 (95% CI 1.26, 2.67; P = .002) and a pooled adjusted OR of 1.71 (95% CI 1.33, 2.19; P < .001). In subgroup analyses, high-dose PPI use was associated with higher odds for hypomagnesemia relative to low-dose PPI use (pooled adjusted OR 2.13; 95% CI 1.26, 3.59; P = .005).
    Srinutta et al., Medicine (Baltimore), 2019 · checked 2026-09-17 · independently re-checked
22. mg-r5-2 · Observational data · meta-analysis of observational studies
    The pooled prevalence of hypomagnesemia in T2DM was 32% (95% CI: 22-36%) out of 4192 cases. On subgroup analysis, the prevalence of hypomagnesemia in male and female were 19.8% and 20.1%, respectively. Geographically, Asia had the highest prevalence of hypomagnesemia with 31.9% (95% CI: 24-41.1%).
    Pitliya et al., Endocrine, 2024 · checked 2026-09-17 · independently re-checked
23. mg-r5-3 · Observational data · meta-analysis of observational studies
    The patients with hypomagnesemia had higher mortality rate (risk ratio [RR] 1.76; 95% confidence interval [CI] 1.54-2.00; P <0.00001), more frequently had sepsis (RR 2.04; 95% CI 1.21-3.42; P = 0.0007) and more frequent need for ventilatory support (RR 1.36; 95% CI 1.21 to 1.53; P <0.00001).
    Jiang et al., Shock, 2017 · checked 2026-09-17 · independently re-checked
24. mg-06 · Meta-analysis or systematic review · trials and qualified health claim review
    Magnesium supplementation only marginally lowers blood pressure
    NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
25. mg-07 · Position of an expert body · expert body position
    The American Diabetes Association states that there is insufficient evidence to support the routine use of magnesium to improve glycemic control in people with diabetes.
    NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
26. mg-08 · Randomised controlled trial(s) · small randomised trials
    Three out of four small, short-term, placebo-controlled trials found modest reductions in the frequency of migraines in patients who were given up to 600 mg/day magnesium.
    NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
27. mg-t1 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis
    the difference in the number of cramps per week at four weeks (MD -0.18 cramps/week, 95% CI -0.84 to 0.49; 5 studies, 307 participants; moderate-certainty evidence)
    Garrison et al., Cochrane Database of Systematic Reviews, 2020 · checked 2026-09-16 · independently re-checked
28. mg-s08 · Meta-analysis or systematic review · systematic review and meta-analysis
    Our findings from the meta-analysis showed a significant decline in depression scores due to intervention with magnesium supplements [standardized mean difference (SMD): -0.919, 95% CI: -1.443 to -0.396, p = 0.001].
    Moabedi et al., Frontiers in Psychiatry, 2023 · checked 2026-09-17 · independently re-checked
29. mg-s09 · Meta-analysis or systematic review · systematic review and meta-analysis
    Future high-quality RCTs with larger sample sizes must be run to interpret this effect of magnesium on depression in clinical settings.
    Moabedi et al., Frontiers in Psychiatry, 2023 · checked 2026-09-17 · independently re-checked
30. mg-r5-4 · Meta-analysis or systematic review · meta-analysis of randomised controlled trials
    The frequency of leg cramps after treatment was not decreased in the treatment group compared to the control group (WMD = -0.47, 95% CI: -1.14-0.20, P = 0.167). Magnesium supplementation cannot improve the recovery from leg cramps compared to the control group (OR = 0.47, 95% CI: 0.14-1.52, P = 0.207).
    Liu et al., Taiwanese Journal of Obstetrics and Gynecology, 2021 · checked 2026-09-17 · independently re-checked
31. mg-r6-01 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of randomised trials
    Major adverse events (occurring in 2 out of 72 magnesium recipients and 3 out of 68 placebo recipients), and withdrawals due to adverse events, were not significantly different from placebo. However, in the four studies for which it could be determined, more participants experienced minor adverse events in the magnesium group than in the placebo group (RR 1.51, 95% CI 0.98 to 2.33; 4 studies, 254 participants; low-certainty evidence).
    Garrison et al., Cochrane Database of Systematic Reviews, 2020 · checked 2026-09-17 · independently re-checked
32. mg-r6-05 · Randomised controlled trial(s) · randomised controlled trial
    The response rate for overall improvement was 11.7% in the placebo group, 69.2% in the senna group, and 68.3% in the MgO group (P < 0.0001). ... The frequency of severe treatment-related adverse events was 0%.
    Morishita et al., American Journal of Gastroenterology, 2021 · checked 2026-09-17 · independently re-checked
33. mg-e1-03 · Observational data · meta-analysis of observational studies
    Our results revealed an inverse association between drinking water magnesium level and CHD mortality (RR = 0.89, 95% CI = 0.79-0.99, I² = 70.6).
    Jiang et al., Nutrients, 2016 · checked 2026-09-18 · independently re-checked
34. mg-e1-04 · Observational data · stated limitation of the evidence base in a meta-analysis
    Four studies came from Sweden, two from Netherlands, two from Finland, one from England and one from China.
    Jiang et al., Nutrients, 2016 · checked 2026-09-18 · independently re-checked
35. mg-e1-10 · Randomised controlled trial(s) · randomised double-blind controlled trial
    At 6 months, the incidence of falls was significantly lower in the SG9 group compared with the J66 group (relative risk reduction 82%; RR = 0.18, 95% CI 0.04-0.88; p < 0.05), whereas no significant between-group difference was observed at 12 months.
    Nutrients, 2026 · checked 2026-09-18 · independently re-checked
36. mg-09 · Position of an expert body · expert body statement
    High doses of magnesium from dietary supplements or medications often result in diarrhea that can be accompanied by nausea and abdominal cramping.
    NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
37. mg-10 · Position of an expert body · expert body statement
    The risk of magnesium toxicity increases with impaired renal function or kidney failure because the ability to remove excess magnesium is reduced or lost.
    NIH Office of Dietary Supplements, Health Professional Fact Sheet: Magnesium · checked 2026-09-15 · extracted
38. mg-r6-02 · Randomised controlled trial(s) · randomised controlled trial
    Among subjects who experienced gastrointestinal adverse effects, 35 were in the group receiving magnesium treatment versus nine in the placebo group. Five deaths and six cardiovascular events occurred in the magnesium group compared with two deaths and no cardiovascular events in the placebo group.
    Bressendorff et al., Journal of the American Society of Nephrology, 2023 · checked 2026-09-17 · independently re-checked
39. mg-r6-03 · Observational data · observational analysis within a randomised controlled trial
    A total of 6147 outpatients had baseline serum magnesium data. Of these, 1082 (17.6%) had magnesium concentrations below .75 mmol/L, 4410 (71.7%) had concentrations within the normal range, and 655 (10.7%) had concentrations above .95 mmol/L. The incidence rate (per 100 person-years) for the primary composite outcome was highest in patients with hypermagnesaemia (34.9, 95% confidence interval 31.2-39.0), while rates were similar between those with hypomagnesaemia (21.5, 19.4-23.8), and normal magnesium (20.9, 19.9-22.0).
    Ferreira et al., European Heart Journal, 2026 · checked 2026-09-17 · independently re-checked
40. mg-r6-04 · Randomised controlled trial(s) · randomised controlled trial
    Magnesium citrate increased plasma (+0.04 mmol/L; 95% CI, +0.02 to +0.06 mmol/L) and urine magnesium (+3.12 mmol/24 h; 95% CI, +2.23 to +4.01 mmol/24 h) compared with placebo. ... One serious adverse event was reported, which was considered unrelated to the study treatment.
    Zhang et al., Journal of the American Heart Association, 2022 · checked 2026-09-17 · independently re-checked
41. mg-e1-13 · Position of an expert body · expert perspective with tabulation of the source studies
    Because no adverse effects caused by food intake were found, a UL of 350 mg (14.6 mmol)/d as an Mg supplement for adolescents and adults was established based on a lowest observed adverse event level (LOAEL) of 360 mg (15 mmol)/d and an uncertainty factor of 1.0.
    Costello & Rosanoff, Advances in Nutrition, 2023 · checked 2026-09-18 · independently re-checked
42. mg-e1-14 · Position of an expert body · expert perspective on evidence quality
    Most of the studies in TABLE 1, TABLE 3 do not indicate the criteria the investigators used to identify diarrhea or whether the criteria conformed to the NIDDK medical definition and duration.
    Costello & Rosanoff, Advances in Nutrition, 2023 · checked 2026-09-18 · independently re-checked
43. mg-e1-15 · Position of an expert body · expert perspective
    Mg gluconate and Mg chloride have been preferred for oral replacement because they cause diarrhea less often than other salt forms [47].
    Costello & Rosanoff, Advances in Nutrition, 2023 · checked 2026-09-18 · independently re-checked
44. mg-e1-16 · Position of an expert body · expert perspective
    As indicated above, taking a high amount of Mg in divided doses instead of in a single dose and taking supplements with food can mitigate the chances of gastrointestinal symptoms [40].
    Costello & Rosanoff, Advances in Nutrition, 2023 · checked 2026-09-18 · independently re-checked
45. mg-11 · Position of an expert body · expert body statement
    Magnesium-rich supplements or medications can decrease the absorption of oral bisphosphonates, such as alendronate (Fosamax), that are used to treat osteoporosis.
    NIH Office of Dietary Supplements, Magnesium - Health Professional Fact Sheet · checked 2026-09-16 · independently re-checked
46. mg-12 · Position of an expert body · expert body statement
    Magnesium can form insoluble complexes with tetracyclines, such as demeclocycline (Declomycin) and doxycycline (Vibramycin), and with quinolone antibiotics, such as ciprofloxacin (Cipro) and levofloxacin (Levaquin).
    NIH Office of Dietary Supplements, Magnesium - Health Professional Fact Sheet · checked 2026-09-16 · independently re-checked
47. mg-13 · Position of an expert body · expert body statement
    Chronic treatment with loop diuretics, such as furosemide (Lasix) and bumetanide (Bumex), and thiazide diuretics, such as hydrochlorothiazide (Aquazide H) and ethacrynic acid (Edecrin), can increase the loss of magnesium in urine and lead to magnesium depletion.
    NIH Office of Dietary Supplements, Magnesium - Health Professional Fact Sheet · checked 2026-09-16 · independently re-checked
48. mg-14 · Position of an expert body · expert body statement
    Prescription proton pump inhibitor (PPI) drugs, such as esomeprazole magnesium (Nexium) and lansoprazole (Prevacid), can cause hypomagnesemia when taken for prolonged periods (typically more than a year).
    NIH Office of Dietary Supplements, Magnesium - Health Professional Fact Sheet · checked 2026-09-16 · independently re-checked