Magnesium Deficiency: Causes, Symptoms and Who Is at Risk
What low magnesium means, why it is uncommon in healthy people, which conditions and medicines are linked to it, why symptoms cannot diagnose it, and why treatment is clinician-led.
Content last updated . This page has not been medically reviewed.
Urgent first
Very low magnesium can be a life-threatening emergency. MedlinePlus says untreated low magnesium can lead to cardiac arrest, respiratory arrest and death, and to contact a provider right away if you have symptoms. [1] In the US, call 911 for convulsions, collapse or trouble breathing. Do not try to fix suspected low magnesium on your own.What the term means
Magnesium deficiency, medically called hypomagnesemia, means the amount of magnesium in the blood is lower than normal. [1] That is different from simply eating less than a reference intake. MedlinePlus explains that reference intakes are used to plan and assess the intakes of healthy people, and it says it is rare to be truly lacking in magnesium. [2] For general background see Magnesium.Causes and who is at risk
MedlinePlus lists these common causes of low magnesium. [1]| Cause | Detail named by the source |
|---|---|
| Alcohol use | Listed as a common cause [1][2] |
| Digestive conditions | Chronic diarrhea; malabsorption such as celiac disease and inflammatory bowel disease; bowel surgery [1][2] |
| Kidney and hormone conditions | Kidney tubule disorders, recovery from acute kidney injury, excess aldosterone [1] |
| Diabetes | Excessive urination in uncontrolled diabetes; type 2 diabetes also listed [1][2] |
| Other | Malnutrition, pancreatitis, large burns, excessive sweating [1] |
| Medicines | Diuretics, proton pump inhibitors, and others such as cisplatin, cyclosporine, tacrolimus and aminoglycoside antibiotics [1] |
MedlinePlus's blood-test page also names older adults and people with malnutrition, and says pregnancy increases the need for magnesium. [3]
Medicines: what the research shows
| Question | What the source found | Strength |
|---|---|---|
| Are proton pump inhibitors linked to low magnesium? | A 2019 meta-analysis of 16 observational studies (131,507 patients) found hypomagnesemia in 19.4% of users versus 13.5% of non-users; pooled adjusted odds ratio 1.71, higher with high-dose use. [4] | Observational association, not proof of cause |
| Which medicine classes are named? | A 2015 review names diuretics, EGFR inhibitors, calcineurin inhibitors and proton pump inhibitors. [5] | Review |
Never stop or change a prescribed medicine because of this page. Ask the prescriber or a pharmacist; see How medication interactions work.
Symptoms, and why they cannot diagnose it
MedlinePlus groups symptoms as early (loss of appetite, nausea, vomiting, fatigue, weakness), moderate (numbness or tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms) and severe (low blood calcium and low blood potassium). [2] These overlap with many other conditions, and high magnesium can cause much the same symptoms. [3] Only a clinician can sort out the cause.Testing and its limits
- A blood test measures magnesium in the blood; MedlinePlus gives a normal range of 1.6 to 2.6 mg/dL and says it varies slightly between laboratories. [1]
- The blood level may be normal even when stored magnesium is low, because the body takes magnesium from bone to keep blood levels stable. [3]
- Serum magnesium reflects only about 1% of body magnesium. [6]
- Clinicians may add calcium, potassium, a metabolic panel, urine magnesium and an electrocardiogram. [1]
- Hair or home mineral panels are not described as diagnostic in the sources we read. See Deficiency testing and its limits.
Treatment is clinician-led
MedlinePlus says treatment depends on severity and the cause, and may include fluids through a vein, magnesium by mouth or vein, and medicines for symptoms. [1] Taking magnesium supplements or laxatives without advice can raise magnesium, and high levels mostly occur in people with kidney failure. [3]Special groups
- Pregnancy and breastfeeding: need increases in pregnancy; ask a clinician before adding supplements. [3] See Pregnancy and breastfeeding safety.
- Children: the sources we read for this page give no child-specific deficiency guidance; talk to a pediatric clinician.
- Kidney disease: kidney problems can cause the body to lose too much magnesium, and kidney failure is the most common cause of high levels. [3] See Minerals and kidney disease.
- Surgery: tell the care team about all supplements; NCCIH notes some may affect bleeding or anesthesia. [7]
Frequently asked questions
Is magnesium deficiency common?
MedlinePlus says it is rare to be truly lacking in magnesium. [2] It is more likely with alcohol misuse, digestive disease, some medicines and type 2 diabetes. [2]
Can I tell I am low from symptoms?
No. Fatigue, weakness, cramps and numbness have many causes, so a clinician needs to assess them. [3]
Does a normal blood test rule out low stores?
Not fully. Blood magnesium can be normal while stored magnesium is low. [3]
Which medicines can lower magnesium?
MedlinePlus names diuretics, proton pump inhibitors and several other drugs. [1] Talk to your prescriber or pharmacist before changing anything.
Do magnesium supplements prevent leg cramps?
A Cochrane review judged it unlikely that magnesium gives meaningful cramp prevention in older adults. [8]
References
- MedlinePlus (US National Library of Medicine). Review date 5/19/2025. MedlinePlus Medical Encyclopedia, Magnesium deficiency. Read 2026-10-22.
- MedlinePlus (US National Library of Medicine). Review date 1/21/2025. MedlinePlus Medical Encyclopedia, Magnesium in diet. Read 2026-10-22.
- MedlinePlus (US National Library of Medicine). MedlinePlus, Magnesium Blood Test. Read 2026-10-22.
- Proton pump inhibitors and hypomagnesemia: A meta-analysis of observational studies. Medicine (Baltimore) 2019. PubMed 31689852. Read 2026-10-22.
- Magnesium in man: implications for health and disease. Physiol Rev 2015. PubMed 25540137. Read 2026-10-22.
- Open-access article indexed in PubMed Central. Predicting and Testing Bioavailability of Magnesium Supplements (Nutrients 2019, PMC6683096). Read 2026-10-22.
- National Center for Complementary and Integrative Health (US), last updated January 2019. NCCIH, Using Dietary Supplements Wisely. Read 2026-10-22.
- Magnesium for skeletal muscle cramps. Cochrane Database Syst Rev 2020. PubMed 32956536. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.