Optimal Health Medical Blog

The Blog of Dr. Henry Sobo



Magnesium is an essential mineral in the body, as it  is a cofactor in more than 300 enzyme systems that regulate many important biochemical reactions. It is involved in protein synthesis, blood glucose regulation, blood pressure regulation and  muscle and nerve functions[13]. Magnesium is an essential element in the production and health of the skeletal system. It is necessary for  energy production through its role in the breakdown of glucose to release energy. It is essential in the process called  oxidative phosphorylation, also an essential energy producing process, and it is required for the synthesis of DNA, and the  antioxidant glutathione. Magnesium is important to the passage of calcium and potassium across cell membranes, essential for normal muscle contraction, nervous system impulses and regulation of heart rhythm[3].


2018 review reported that magnesium deficiency  increases a person’s risk of cardiovascular disease. Studies have found that magnesium deficiency is common in people with congestive heart failure and makes successful treatment more difficult. People  who received magnesium soon after a heart attack had a lowered death rate as a result. And the use of  magnesium as a  part of treatment for congestive heart failure reduces the risk of arrhythmia– abnormal heart rhythm.

2019 meta-analysisTrusted Source, found that  magnesium intake lowers a person’s risk of stroke. They reported that for each 100 mg per day intake of magnesium, it  lowered  stroke risk by  2%.

Magnesium plays a role in hypertension. According to the Office of Dietary SupplementsTrusted Source (ODS), taking magnesium supplements modestly lowers blood pressure .

Migraine headaches

According to Trusted Source magnesium may prevent or relieve headaches because  magnesium deficiency affects neurotransmitters and also causes  blood vessel constriction, two factors linked to migraine headache.

It was found that people who suffer from migraines have lower levels of magnesium in their blood and body tissues when compared with others. A systematic review from 2017Trusted Source said that taking 600mg of magnesium citrate is a safe and effective way to prevent migraines. The American Migraine Foundation officially  recommends an intake of 400500 mg per day for migraine prevention. Read more about magnesium for migraine.

Premenstrual syndrome

Magnesium may also play a role in premenstrual syndrome (PMS). A 2012 articleTrusted Source, article recommended  taking magnesium supplements along with vitamin B-6 to improve PMS symptoms. The American College of Obstetricians and Gynecologists say that taking magnesium supplements may help to reduce bloating, and improve mood symptoms, and breast tenderness .


Magnesium deficiency may play a role in mood disorders, such as  depression and anxiety. A systematic review from 2017Trusted Source said that low magnesium levels correlate with higher levels of anxiety. This is felt to be due to the effects of magnesium being essential to the coordinated functioning of the hypothalamus, pituitary and adrenal glands which work together in the physiologic system known as the HPA  (hypothalamic-pituitary-adrenal) axis, consisting of  three glands that are activated by stress.


Higher magnesium intake in the diet may lower the  risk of type 2 diabetes. This is due, according to Trusted Source, to magnesium’s role in glucose control and insulin metabolism. Thus,  magnesium deficiency  worsens insulin resistance, the physiologic state commonly preceding the development of type 2 diabetes. It may also be the case that insulin resistance may cause lowering of  magnesium levels, again highlighting the benefit of magnesium supplementation for those at risk

Bone health

Calcium and magnesium working side by side with other minerals (zinc, manganese, selenium) are essential for bone health and  healthy bone formation. Research from 2013Trusted Source showed that good magnesium intake is associated with higher bone density  and a lower risk of osteoporosis in  menopausal females . Magnesium also plays a role in regulating Vit D, another nutrient important for bone health.


Magnesium is found in abundance in  Green leafy vegetables such as spinach, legumes, nuts, seeds, and whole grains [1,3]. Foods that  contain  dietary fiber provide magnesium. It is also added to breakfast cereals and other fortified foods.

Mineral, and bottled waters are also sources of magnesium [8].

The following are foods that are the richest in magnesium content

Magnesium Content in milligrams (mg) per serving [10]

(mg) per
Pumpkin seeds, roasted, 1 ounce156
Chia seeds, 1 ounce111
Almonds, dry roasted, 1 ounce80
Spinach, boiled, ½ cup78
Cashews, dry roasted, 1 ounce74
Peanuts, oil roasted, ¼ cup63
Cereal, shredded wheat, 2 large biscuits61
Soymilk, plain or vanilla, 1 cup61
Black beans, cooked, ½ cup60
Edamame, shelled, cooked, ½ cup50
Peanut butter, smooth, 2 tablespoons49
Potato, baked with skin, 3.5 ounces43
Rice, brown, cooked, ½ cup42
Yogurt, plain, low fat, 8 ounces42
Breakfast cereals, fortified with 10% of the DV for magnesium, 1 serving42
Oatmeal, instant, 1 packet36
Kidney beans, canned, ½ cup35
Banana, 1 medium32
Salmon, Atlantic, farmed, cooked, 3 ounces26
Milk, 1 cup24–27

Dietary supplements

Magnesium supplements are available in a variety of forms, including magnesium oxide, citrate, and chloride [2,3]. The Supplement Facts panel on  dietary supplement labels tells you  the amount of elemental magnesium contained in the supplement, not the weight of the entire magnesium-containing capsule or tablet.

There is an important difference in the absorption of magnesium from different kinds of magnesium supplements. Forms of magnesium that dissolve well in liquid are more completely absorbed in the gastrointestinal tract [2,12]. Some studies have found that magnesium in the aspartate, citrate, lactate, and chloride forms is absorbed better and is more bioavailable than magnesium oxide and magnesium sulfate [1216]. One caution is that high doses of zinc from supplements (142 mg/day) interfere with magnesium absorption and disrupt the body’s magnesium balance [17].


Symptomatic magnesium deficiency due to low dietary intake in otherwise-healthy people is uncommon because the kidneys limit urinary excretion of this mineral [3]. However, habitually low intakes or excessive losses of magnesium due to certain health conditions, chronic alcoholism, and/or the use of certain medications can lead to magnesium deficiency.

Early signs of magnesium deficiency include loss of appetite, nausea, vomiting, fatigue, and weakness. As magnesium deficiency worsens, numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms can occur [1,2]. Severe magnesium deficiency can result in hypocalcemia or hypokalemia (low serum calcium or potassium levels, respectively) because mineral homeostasis is disrupted [2].

Groups at Risk of Magnesium Inadequacy

 The following groups are more likely than others to be at risk of magnesium inadequacy because they typically consume insufficient amounts or they have medical conditions (or take medications) that reduce magnesium absorption from the gut or increase losses from the body.

People with gastrointestinal disease

Crohn’s disease (gluten-sensitive enteropathy)  results in chronic diarrhea and fat malabsorption resulting in magnesium depletion over time 2. Resection or bypass of the small intestine also leads to malabsorption and magnesium loss [2].

People with type 2 diabetes

Low Magnesium status occurs due to increased urinary magnesium output in people with insulin resistance and/or type 2 diabetes [25,26]. This is the result of their  higher concentrations of glucose in the kidneys which  increases the  urine output of magnesium [2].

People with alcohol dependence

Magnesium deficiency is common in people with alcoholism [2], due to poor dietary intake. They also exhibit  gastrointestinal problems like vomiting, and diarrhea, which causes excess excretion of magnesium into the urine.

The elderly

Older adults tend to have  lower dietary intakes of magnesium[21,28]. They may also have a decreased magnesium absorption from the gut as well as increased kidney excretion of magnesium [29]. Older individuals are also more likely to have chronic diseases or take medications that alter magnesium status, increasing their risk of magnesium depletion [1,30].

Health Risks from Excessive Magnesium

Ingesting a lot of magnesium in foods will not pose any health risk  because the kidneys eliminate excess amounts in the urine [29]. if a person ingests a lot of magnesium in supplements however they may suffer side effects such as  diarrhea which may be accompanied by nausea and abdominal cramping [1].

Very large doses of magnesium-containing laxatives and antacids (typically providing more than 5,000 mg/day magnesium) have been associated with magnesium toxicity [58]. Symptoms of magnesium toxicity are low blood pressure, nausea, vomiting, facial flushing, retention of urine, depression, and lethargy before progressing to muscle weakness, difficulty breathing, extreme hypotension, irregular heartbeat, [29]. The risk of magnesium toxicity increases with impaired renal function or kidney failure. Such individuals should not take magnesium supplements except under the direction of a physician in a closely monitored situation because with kidney dysfunction the ability to remove excess magnesium is greatly reduced [1,29].

Magnesium and Medication Interactions

Some medications may affect the body’s magnesium status. People taking these should ask their doctor if any medication adjustments are warranted.

Bisphosphonates such as Fosamax for osteoporosis

Magnesium may  decrease the absorption of oral bisphosphonates, (Fosamax) [61]. Magnesium supplements should be separated by at least 2 hours [57].


There are two types of antibiotics that should be taken at least 2 hours before, or 4 hours after a magnesium-containing supplement [57,62]. These are the  tetracyclines, such as demeclocycline (Declomycin) and doxycycline (Vibramycin) and the  quinolone antibiotics, such as ciprofloxacin (Cipro) and levofloxacin (Levaquin).


Diuretics may  increase the excretion of magnesium in the urine lowering the body’s levels. These are the loop diuretics  furosemide (Lasix) and bumetanide (Bumex), and the thiazide diuretics, such as hydrochlorothiazide (Aquazide H) and ethacrynic acid (Edecrin) [63].

There is also a type of diuretic which reduces magnesium excretion-they are called potassium-sparing diuretics, such as amiloride (Midamor) and spironolactone (Aldactone), reduce magnesium excretion [63].

Proton pump inhibitors (PPIs)

Prescription proton pump inhibitor  drugs, such as Nexium and Prevacid), deplete magnesium levels when taken for a prolonged period-over a year[64].  As a result of this information coming to light the FDA advises health care professionals to consider measuring patients’  magnesium levels prior to starting long -term PPI treatment and to check magnesium levels during treatment [64].ls caused by PPIs. In order to have a patient replete their magnesium levels with supplementation they need to discontinue the medication as it will block proper absorption of the magnesium.

Magnesium and Healthful Diets

The federal government’s 2020–2025 Dietary Guidelines for Americans describes a healthy diet as one that notes that contains many of the magnesium rich foods. They advise the following:

  • A variety of vegetables; fruits; grains (at least half whole grains); fat-free and low-fat milk, yogurt, and cheese; and oils.
    • Whole grains and dark-green, leafy vegetables are good sources of magnesium. Low-fat milk and yogurt contain magnesium as well. Some ready-to-eat breakfast cereals are fortified with magnesium.
  • A variety of protein foods such as lean meats; poultry; eggs; seafood; beans, peas, and lentils; nuts and seeds; and soy products.
    • Dried beans and legumes (such as soybeans, baked beans, lentils, and peanuts) and nuts (such as almonds and cashews) provide magnesium.
  • Limit foods and beverages higher in added sugars, saturated fat, and sodium.
  • Limit alcoholic beverages.