Magnesium: Sources, Benefits, and Risks

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Magnesium: Sources, Benefits, and Risks

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What is Magnesium?

Magnesium is one of the vital micronutrients in our bodies. It is the 4th most abundant mineral in the human body after calcium, sodium, and potassium. It is also the second most common intracellular cation after potassium. 

There are approximately 25 grams of the total magnesium in an average adult.

Approximately 27% is present in muscles, 19% in soft tissues, and 53% is present in bones. Less than 1% is present in the blood. Yet the serum magnesium levels are measured for magnesium levels in the body (1, 2).

More than 300 enzymatic reactions involve magnesium. Blood pressure regulation, protein synthesis, heart function, glucose regulation, and nerve function are some of the important functions where magnesium plays a crucial role (3).

What are Magnesium sources?

Food sources of magnesium are:

  • Leafy green vegetables (e.g. broccoli),
  • Seeds (pumpkin, sesame, sunflowers, flaxseed),
  • Almonds
  • Bananas
  • Unprocessed cereals
  • Meat
  • Fish
  • Fruits
  • Milk products

Water is a natural source of magnesium. Water accounts for 10% of the magnesium requirement. However, water treatment removes many of the natural minerals including magnesium. Thus, over the years water has become a negligible source of magnesium. 

Here are some of the food sources of magnesium and quantity per serving as per the US Department of Health and Human Service (4).

Seeds and Nuts

FoodServing sizemilligram per servingPercent Daily Value
Pumpkin seeds, roasted1 ounce15637
Chia seeds1 ounce11126
Almonds, dry roasted1 ounce8019
Cashews, dry roasted1 ounce7418
Peanuts, oil roasted¼ cup6315


FoodServing sizemilligram per servingPercent Daily Value
Cereal, shredded wheat2 large biscuits6115
Potato, baked with skin3.5 ounces4912
Rice, brown, cooked½ cup4210
Breakfast cereals, fortified1 serving4210
Oatmeal, instant1 packet369
Banana1 medium328
Bread, whole wheat1 slice235
Rice, white, cooked½ cup102


FoodServing sizemilligram per servingPercent Daily Value
Edamame, shelled, cooked½ cup5012
Avocado, cubed½ cup225
Broccoli, chopped and cooked½ cup123


FoodServing sizemilligram per servingPercent Daily Value
Salmon, Atlantic, farmed, cooked3 ounces266
Halibut, cooked3 ounces246
Chicken breast, roasted3 ounces225
Beef, ground, 90% lean, pan-broiled3 ounces205


FoodServing sizemilligram per servingPercent Daily Value
Soymilk, plain or vanilla1 cup6115
Peanut butter, smooth2 tablespoons4912
Yogurt, plain, low fat8 ounces4210
Kidney beans, canned½ cup358
Milk1 cup24-276
Raisins½ cup235
Apple1 medium92
Carrot, raw1 medium72

Can you take Magnesium supplements?

If food sources are inadequate, magnesium supplements can also be used. Several clinical studies have shown increased serum magnesium levels after magnesium supplement treatment.

Magnesium can either be used:

  • Oral tablets or
  • Topical magnesium oils

Most of the magnesium tablets are magnesium salts such as magnesium citrate, magnesium malate, and magnesium glycinate.

Organic magnesium compounds such as magnesium chlorides and magnesium citrate are easily absorbed compared to inorganic compounds such as magnesium sulfate (5).

Although, the best way to improve magnesium levels in the body is diet, magnesium tablets are a cheap and easily available alternative. 

Magnesium cream or magnesium oils are suitable for individuals who may suffer from the side effects of oral tablets. Magnesium cream or oil readily absorbs via the skin (6).

Epsom salt (magnesium sulfate) baths have been used for centuries to treat many health conditions in traditional medicine. Epsom salts baths are shown to increase blood magnesium levels because the magnesium is absorbed via the skin (7).

What is recommended daily intake of magnesium?

The United States Food and Nutrition Board recommends a daily magnesium intake of 420 mg for men and 320 mg for women. But 60% of the US population fails to get the recommended daily amounts (8).

The recommended dietary allowances (RDA) according to gender and age is given below in milligrams (9).

Birth: 6 months3030
7–12 months7575
1–3 years8030
4–8 years130130
9–13 years240240
14–18 years410360400360
19–30 years400310300310

What are The Health benefits of Magnesium? 

Hypomagnesaemia or magnesium deficiency is defined by serum concentration of magnesium below 0.74 mmol/L (10).

Hypomagnesaemia is prevalent among 2.5 to 15% of the general population (11). 

Adequate levels of magnesium in the body can help reduce the risk of diseases. Thus, the benefits of magnesium are associated with having a good level of magnesium in the body, and diseases are correlated with deficiency of magnesium.

Here are some of the health benefits associated with magnesium.

Magnesium is vital for bone health

Taking magnesium in higher quantities is associated with a greater bone mineral density among whites (12). Reduced bone mineral density is the hallmark of osteoporosis (13).

Increased bone turnover is associated with weak bones and the risk of fracture. Magnesium supplementation decreased the bone turnover in postmenopausal osteoporotic women (14).

Also, magnesium supplementation (magnesium hydroxide) reduces fractures and increases bone density in menopausal women (15).

Calcium and Vitamin D are important for maintaining bone health. Magnesium is required to convert vitamin D into its active form. Vitamin D in turn is required for calcium absorption (16).

For this reason, many Ricketts patients are deficient in magnesium and require magnesium supplements (17).

Thus, magnesium is an important mineral that regulates vitamin D and calcium and protects our bones from decaying and keeps our bones in a healthy state.

Magnesium can help with depression and anxiety

For the past 100 years, magnesium has been used for the treatment of depression.

Research shows that magnesium works quickly to reduce depression symptoms. Magnesium is safe and effective regardless of gender and age. It works well for mild to moderate depression symptoms (18).

More magnesium intake is associated with lower depression and vice versa (19).

Some studies have even suggested using magnesium for adjuvant therapy of depression (20).

Magnesium supplementation has been associated with rapid recovery of depression in patients suffering from major depression (21).

Symptoms of depression in type 2 diabetes T2DM patients can be reduced by treatment with magnesium supplements (22).

In summary, magnesium high magnesium levels are associated with low depression status, and magnesium can help reduce the symptoms of depression regardless of gender or age.  

Magnesium improves diabetes management 

Magnesium is an important micronutrient to improve diabetes management. 

Research shows that magnesium intake decreases fasting glucose and insulin levels (23).

Magnesium intake is associated with lower incidences of diabetes. High magnesium intake is also associated with lower inflammatory markers such as hs-CRP and IL-6  (24,25).

One research found that taking magnesium at 100mg/day reduces the risk of diabetes by about 15% (26).

The risk of type 2 diabetes T2DM is significantly reduced by people who consume magnesium compared to people who do not consume magnesium (27). Moreover, renal (kidney) function declines quicker in type 2 diabetes patients with lower magnesium (28).

Neuropathy progression is seen to slow down in patients who regularly consume magnesium (29).

In summary, Intake of magnesium is also associated with a low incidence of diabetes as well as the symptoms. Magnesium intake is also associated with a reduction in inflammation markers.

Magnesium is good for the heart health

Magnesium deficiency is associated with an increased risk of heart failure, complex ventricular arrhythmias (infrequent heartbeat), and atrial fibrillation (elevated heartbeat). Magnesium supplementation can help in reversing the conditions of arrhythmias (30,31,32).

Research shows that heart failure and all-cause mortality are prevalent in elderly patients with magnesium deficiency (33).

Both human and animal research has shown that magnesium deficiency is associated with atherosclerosis and increased risk of cardiovascular diseases (34,35)

People with dietary magnesium status have fewer cardiovascular events. Moreover, low magnesium serum levels are associated with a high risk of these events (36).

The deficiency of magnesium is also associated with an increased risk of coronary heart disease (37). 

Magnesium treatment is shown to reduce overall cholesterol and LDL (38).

Consumption of water with magnesium is shown to reduce cardiovascular diseases by 30-35% (39). 

Therefore, magnesium supplemented water can be useful in getting daily required magnesium. 

Magnesium salts are effective against preeclampsia and eclampsia because of magnesium’s vasodilating effect. Magnesium salt treatment can reduce the risk of preeclampsia by 50% (40,41).

Thus, magnesium deficiency is associated with different heart conditions such as atherosclerosis, heart failure, coronary heart disease, and arrhythmias. The use of magnesium supplements can reduce these risks.

Other benefits: 

Magnesium and skin: 

Magnesium is known to improve skin hydration and inflammation symptoms (42). Magnesium levels are lower in children with atopic dermatitis (43). 

Magnesium cream with ceramides is shown to be effective in reducing symptoms of mild to moderate topic dermatitis. The effect was as good as hydrocortisone creams (44).

Magnesium and pregnancy: 

Magnesium deficiency is associated with a difficult pregnancy and the health of the baby (45). Magnesium supplementation reduces the risks of preterm births and low-weight newborns (46).

Magnesium can help with migraine:

Magnesium treatment is recommended for migraine headaches. Oral supplementation is shown to significantly reduce headache frequency, duration, and intensity (47,48).

Magnesium and metabolic syndrome:

Magnesium deficiency is associated with low-grade chronic inflammation (49).

C-reactive proteins (CRP) are among the indicators of inflammation. An increase in CRP is associated with low serum magnesium levels (50).

Fetal magnesium deficiency is associated with an increased risk of metabolic syndrome later in life (51).

Magnesium reduces insomnia and sleeplessness

Magnesium supplementation was shown to improve sleep time, sleep quality, the concentration of serum renin and melatonin (52). 

Melatonin is an important hormone for controlling the sleep-wake cycle and an inducer of sleep (53).

Magnesium overdose risks

The prevalence of excessive magnesium levels is not common. But high levels are detrimental to health. 

Hypermagnesaemia or elevated level of magnesium is associated with hospitalization and may also require medical intervention.

Magnesium serum concentration between 0.70 and 1.0 mmol/L is considered normal magnesium in the body. Magnesium concentration above is 1.0 mmol/L considered Hypermagnesaemia

Overdose of magnesium by accidental ingestion is reported to cause severe health issues such as nausea, vomiting, urinary retention, kidney problems, sleeplessness, paralysis, respiratory depression, and complete heart blockage (54,55,56).

The Gist

Magnesium is a vital micronutrient involved in more than 3000 enzymatic reactions. Unfortunately, a significant percentage of the population does not consume adequate quantities of magnesium. Magnesium deficiency is shown to cause many health problems. 

A diet rich in magnesium or magnesium supplements can help reduce the deficiency of magnesium.