A critical low magnesium level (severe hypomagnesemia) is generally defined as a serum (blood) level below 1.25 mg/dL (0.50 mmol/L), with levels less than 0.5 mmol/L also indicating severe deficiency, requiring immediate attention due to risks of seizures, arrhythmias, and potentially sudden death. While normal levels are around 1.8-2.2 mg/dL, levels below 1.8 mg/dL are considered low, but <1.25 mg/dL is the threshold for severe cases.
If the level of magnesium in your blood is lower than 1.8 milligrams per deciliter, your levels are considered low. If your level is below 1.25 mg/dL, your condition is considered severe. Often, doctors may not find this condition until the levels are severely low. This is when symptoms often first appear.
If you're experiencing symptoms of hypomagnesemia, you should see your healthcare provider. If you have severe symptoms, such as seizures or an abnormal heartbeat, call 911 or get to the nearest hospital as soon as possible.
Normal serum magnesium levels are between 1.46 and 2.68 mg/dL. Hypomagnesemia is an electrolyte disturbance caused by a low serum magnesium level of less than 1.46 mg/dL in the blood. However, this condition is typically asymptomatic until serum magnesium concentration is less than 1.2 mg/dL (0.5 mmol/L).[1]
Recommended dosing by the Critical Care Pharmacotherapy text for patients with GFR >50 ml/min: Mild hypomagnesemia (1.6-1.8 mg/dL): weight/16 = grams of IV magnesium sulfate over 24 hrs. Moderate hypomagnesemia (1.2-1.5 mg/dL): weight/8 = grams of IV magnesium sulfate over 24 hrs.
Magnesium deficiency is usually treated with magnesium supplements. Sometimes these can give you diarrhoea. If this happens, your doctor can adjust your dose. If your levels are very low, you may need to be given magnesium by an intravenous (IV) drip in hospital.
Intravenous magnesium sulfate has been proven to be effective in the treatment of various dysrhythmias, and there is sufficient support for its use in myocardial infarction, preeclampsia, and eclampsia to warrant the attention of emergency nurses.
Every organ in the body, especially the heart, muscles, and kidneys, needs the mineral magnesium. It also contributes to the makeup of teeth and bones. Magnesium is needed for many functions in the body. This includes the physical and chemical processes in the body that convert or use energy (metabolism).
Severe hypermagnesemia (levels greater than 12 mg/dL) can lead to cardiovascular complications (hypotension, and arrhythmias) and neurological disorder (confusion and lethargy). Higher values of serum magnesium (exceeding 15 mg/dL) can induce cardiorespiratory arrest and coma.
For acute deficiency symptoms, such as muscle and leg cramps, supplementation should be continued even after the symptoms have subsided. This is because, depending on the severity of the deficiency, it can take several weeks to replenish magnesium stores.
Among the known magnesium deficiency causes are prescription medications such as diuretics, antibiotics, painkillers and cortisone, which can deplete magnesium levels in the body by impairing absorption or by increasing excretion by the kidneys.
For drinks high in magnesium, opt for mineral waters, fruit juices (especially orange, cherry, watermelon), plant-based milks (soy, almond), and homemade concoctions using raw cacao, coconut milk, or magnesium powders mixed with water or smoothies, with hot chocolate (made with raw cacao) and herbal teas (like nettle) also being good choices.
Normal Results
The normal range for blood magnesium level is 1.7 to 2.2 mg/dL (0.85 to 1.10 mmol/L). Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
A link between Mg deficiency and sudden death is suggested by a substantial number of studies published over the past three decades. Data come from epidemiologic, autopsy, clinical, and animal studies.
Good sources of magnesium include green leafy vegetables, legumes, nuts, seeds, whole grains, and certain beverages. Magnesium may also be added to some breakfast cereals and other fortified foods. In general, approximately 30% to 40% of the magnesium obtained from food and beverages is absorbed by the body.
However, despite this mineral's importance, it is poorly understood from several standpoints, not the least of which is its unique mechanism of absorption and sensitive compartmental handling in the body, making the determination of magnesium status difficult.
Usually, the magnesium level becomes low because people consume less (most often, because of starvation) or because the intestine cannot absorb nutrients normally (called malabsorption). But sometimes hypomagnesemia develops because the kidneys or intestine excrete too much magnesium.
A normal serum (blood) magnesium level is 1.8 to 2.2 milligrams per deciliter (mg/dL). Serum magnesium lower than 1.8 mg/dL is considered low. A magnesium level below 1.25 mg/dL is considered very severe hypomagnesemia.
You can conveniently measure your serum magnesium levels with our at-home Magnesium Blood Test kit. You'll receive everything you need to take a blood sample using a finger prick test kit and return your sample to our lab, to receive your result within 2 working days.
Magnesium deficiency can cause a wide variety of features including hypocalcaemia, hypokalaemia and cardiac and neurological manifestations. Chronic low magnesium state has been associated with a number of chronic diseases including diabetes, hypertension, coronary heart disease, and osteoporosis.
Mg is essential in the metabolism of vitamin D, and taking large doses of vitamin D can induce severe depletion of Mg. Adequate magnesium supplementation should be considered as an important aspect of vitamin D therapy.
Culprit medications linked to hypomagnesemia include antibiotics (e.g. aminoglycosides, amphotericin B), diuretics, antineoplastic drugs (cisplatin and cetuximab), calcineurin inhibitors, and proton pump inhibitors.
It is a common treatment for cardiac arrhythmias and hypertension since magnesium is effective for regulating blood pressure and ensuring a healthy heart. It is also used for Lyme disease treatment, as well as for insomnia and dehydration treatment.
Symptoms of magnesium deficiency may include:
Certain medications should not be taken with magnesium, including certain antibiotics, PPI drugs, diuretics, bisphosphonates, and high doses of zinc. If you take any of these medications and might need to supplement your diet with magnesium, speak to your healthcare provider.