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This is one of the longer and more technical blogs I have written. There is SO much information out there it was hard to “keep it simple…” But here it is and I hope you enjoy it and benefit from it.


Magnesium is needed for more than 300 biochemical reactions in the body. It helps to maintain normal nerve and muscle function, supports a healthy immune system, keeps the heartbeat steady, and helps bones remain strong. It also helps adjust blood glucose levels. It aids in the production of energy and protein.

Magnesium is a cofactor in the important enzyme systems that regulate muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium is required for energy production, oxidative phosphorylation, and glycolysis. It contributes to the structural development of bone and is required for the synthesis of DNA, RNA, and the antioxidant glutathione. Magnesium also plays a role in the active transport of calcium and potassium ions across cell membranes, a process that is important to nerve impulse conduction and muscle action. An adult body contains approximately 25 g magnesium, with 50% to 60% present in the bones and most of the rest in soft tissues. Less than 1% of total magnesium is in blood serum, and these levels are kept under tight control.  Magnesium can be released into the blood stream in times of deficiency. However, the proportion of bone magnesium in this exchangeable form declines with age.

Magnesium balances in the blood are largely controlled by the kidney, which typically excretes about 120 mg magnesium into the urine each day. Urinary excretion is reduced when magnesium status is low.

Magnesium is also involved in bone formation and influences the activities of osteoblasts and osteoclasts. Magnesium also affects the concentrations of both parathyroid hormone and the active form of vitamin D, which are major regulators of bone maintenance. Several studies have found associations between magnesium intake and bone mineral density.

Magnesium is widely distributed in plant and animal foods and in beverages. Green leafy vegetables, such as spinach, legumes, nuts, seeds, and whole grains, are good sources. In general, foods containing dietary fiber provide magnesium. Magnesium is also added to some breakfast cereals and other fortified foods. Some types of food processing, such as refining grains in ways that remove the nutrient-rich germ and bran, lower magnesium content substantially.

On the next page is a list of magnesium containing foods. This is from

Tap, mineral, and bottled waters can also be sources of magnesium, but the amount of magnesium in water varies by source and brand (ranging from 1 mg/L to more than 120 mg/L)

Women need about 320 mg per day, men need about 420 mg.

Symptoms of magnesium deficiency due to low dietary intake is uncommon because the kidneys limit urinary excretion of this mineral, 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. Severe magnesium deficiency can result in low serum calcium or potassium.

Dietary surveys of people in the United States consistently show that intakes of magnesium are lower than recommended amounts. I suspect this might be due to our general eating habits. When supplements were included, average total intakes of magnesium were 449 mg for men and 387 mg for women, well above required levels.

Magnesium inadequacy can occur when intakes fall below the Recommended Daily Amount but are above the amount required to prevent deficiency. 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 diseases: the chronic diarrhea and fat malabsorption resulting from Crohn’s disease, celiac disease, and regional enteritis can lead to magnesium depletion over time

People with type 2 diabetes or insulin resistance– higher concentrations of glucose in the kidney can increase the output of magnesium

People with alcohol dependence: pancreatitis, kidney dysfunction, phosphate depletion and ketoacidosis can all develop magnesium deficiencies.

Older adults have lower dietary intakes of magnesium than younger adults. In addition, magnesium absorption from the gut decreases and renal magnesium excretion increases with age. Older adults are also more likely to have chronic diseases or take medications that alter magnesium status, which can increase their risk of magnesium depletion.

Habitually low intakes of magnesium can cause changes in biochemical pathways that can increase the risk of illness over time.

People with the highest blood levels of magnesium were significantly associated with a lower risk of cardiovascular disease, and higher dietary magnesium intakes (up to approximately 250 mg/day) were associated with a significantly lower risk of ischemic heart disease caused by a reduced blood supply to the heart muscle. Higher magnesium intakes might reduce the risk of stroke. Now it could be that higher levels of some other nutrient, along with magnesium, caused these results.

Only a few small, short-term clinical trials have examined the potential effects of supplemental magnesium on these disorders, and the results are unclear. No one has measured the effect of dietary sugar on the levels of magnesium, so we have no information about that, and these studies are preliminary at best.

And some studies have connected magnesium deficiency with a higher risk of osteoporosis. And a few studies say increasing magnesium intakes from food or supplements might increase bone mineral density in postmenopausal and elderly people. So, consider eating enough magnesium to help protect your bones. Even though it isn’t fully proven yet, it will do no harm to consume the recommended amounts.

Magnesium deficiency is related to factors that promote headaches. People who experience migraine headaches may be helped by 300 mg magnesium twice a day, either alone or in combination with medication, to prevent migraines.  Check with your doctor first.

Too much magnesium from food does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts in the urine. High doses of magnesium from dietary supplements or medications often result in nausea and diarrhea. So please do not take more than the recommended amounts without speaking to your doctor first. Magnesium is one of the few nutrients that is actually able to cross the blood-brain barrier in certain forms and can affect brain function. Because of its effect on brain function, magnesium supplements are sometimes prescribed for influencing your mood.

Magnesium can also affect the power of antibiotics and diuretics and other medications. If you choose to take this as a supplement, talk with your doctor first.

I am amazed at the power of magnesium in our bodies. From the brain to the kidneys, it has its effects. And no one has studied how it is absorbed and metabolized. But maybe your feelings of exhaustion, muscle aches, etc. are related to this mineral. Please take a look at the list of food sources on the next page. Are you getting enough? Notice that your favorite binge foods are probably not on the list. The body needs adequate amounts of nutrients to keep you well and happy. What are the changes you need to make?

Thank you for taking the time to read all of this.  Please call if you have a question.

Blessings to you,



Food Milligrams
(mg) per
Almonds, dry roasted, 1 ounce 80 20
Spinach, boiled, ½ cup 78 20
Cashews, dry roasted, 1 ounce 74 19
Peanuts, oil roasted, ¼ cup 63 16
Cereal, shredded wheat, 2 large biscuits 61 15
Soymilk, plain or vanilla, 1 cup 61 15
Black beans, cooked, ½ cup 60 15
Edamame, shelled, cooked, ½ cup 50 13
Peanut butter, smooth, 2 tablespoons 49 12
Bread, whole wheat, 2 slices 46 12
Avocado, cubed, 1 cup 44 11
Potato, baked with skin, 3.5 ounces 43 11
Rice, brown, cooked, ½ cup 42 11
Yogurt, plain, low fat, 8 ounces 42 11
Breakfast cereals, fortified with 10% of the DV for magnesium 40 10
Oatmeal, instant, 1 packet 36 9
Kidney beans, canned, ½ cup 35 9
Banana, 1 medium 32 8
Salmon, Atlantic, farmed, cooked, 3 ounces 26 7
Milk, 1 cup 24–27 6–7
Halibut, cooked, 3 ounces 24 6
Raisins, ½ cup 23 6
Chicken breast, roasted, 3 ounces 22 6
Beef, ground, 90% lean, pan broiled, 3 ounces 20 5
Broccoli, chopped and cooked, ½ cup 12 3
Rice, white, cooked, ½ cup 10 3
Apple, 1 medium 9 2
Carrot, raw, 1 medium 7 2

Chart From

I apologize, I neglected to add these references.  Most of the article above was adapted from information on these sites:

Blessings to you,


4 Responses to Magnesium

  1. Cari Heumann October 15, 2019 at 12:02 pm #

    Theresa, thank you so much for sharing this blog series on minerals. I loved reading about the science behind what they do, how they help our bodies, and the foods that contain them. Society often fails to realize that the lack of proper nutrition and vitamin/mineral deficiencies may actually be the culprit behind many health problems. I have incorporated the consumption of several vitamin and mineral supplements into my daily routine and have noticed a positive difference!
    Theresa, thank you you for all that you do. You have made and continue to make a profound difference in the lives of others, including my own!

    • H. Theresa Wright October 15, 2019 at 1:51 pm #

      Cari, Thank you so much for these kind words.

  2. martha r. wrigley October 15, 2019 at 2:55 pm #

    Thanks, Theresa for the 411 on magnesium.

    • H. Theresa Wright October 25, 2019 at 4:08 pm #

      Glad you enjoyed it.

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